SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  companies.company as company_name, 
  popularity.total as popularity, 
  IF(
    shared_prices.product_id IS NOT NULL, 
    MIN(
      IF (
        shared_prices.percentage_discount = 0, 
        shared_prices.price, 
        shared_prices.price - (
          shared_prices.price * shared_prices.percentage_discount
        ) / 100
      )
    ), 
    MIN(
      IF (
        prices.percentage_discount = 0, 
        prices.price, 
        prices.price - (
          prices.price * prices.percentage_discount
        ) / 100
      )
    )
  ) as price, 
  products.product_type, 
  products.parent_product_id, 
  products.list_price as list_price, 
  MAX(
    100 - (
      (prices.price * 100) / products.list_price
    )
  ) AS sales_discount, 
  IF(
    COUNT(
      IF(
        vi_categories.company_id = products.company_id, 
        NULL, vi_categories.company_id
      )
    ), 
    'Y', 
    'N'
  ) as is_shared_product 
FROM 
  vi_products as products 
  LEFT JOIN vi_product_features_values ON vi_product_features_values.product_id = products.product_id 
  AND vi_product_features_values.lang_code = 'pt' 
  LEFT JOIN vi_product_features ON vi_product_features_values.feature_id = vi_product_features.feature_id 
  LEFT JOIN vi_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'pt' 
  LEFT JOIN vi_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN vi_product_prices as prices_2 ON prices.product_id = prices_2.product_id 
  AND prices_2.lower_limit = 1 
  AND prices_2.price < prices.price 
  AND prices_2.usergroup_id IN (0, 0, 1) 
  LEFT JOIN vi_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN vi_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN vi_categories ON vi_categories.category_id = products_categories.category_id 
  AND (
    vi_categories.usergroup_ids = '' 
    OR FIND_IN_SET(0, vi_categories.usergroup_ids) 
    OR FIND_IN_SET(1, vi_categories.usergroup_ids)
  ) 
  AND vi_categories.status IN ('A', 'H') 
  AND vi_categories.storefront_id IN (0, 1) 
  LEFT JOIN vi_product_popularity as popularity ON popularity.product_id = products.product_id 
  LEFT JOIN vi_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'pt' 
  LEFT JOIN vi_ult_product_prices as shared_prices ON shared_prices.product_id = products.product_id 
  AND shared_prices.lower_limit = 1 
  AND shared_prices.usergroup_id IN (0, 0, 1) 
  AND shared_prices.company_id = 1 
  LEFT JOIN vi_ult_product_prices as shared_prices_2 ON shared_prices.product_id = shared_prices_2.product_id 
  AND shared_prices_2.company_id = 1 
  AND shared_prices_2.lower_limit = 1 
  AND shared_prices_2.price < shared_prices.price 
  AND shared_prices_2.usergroup_id IN (0, 0, 1) 
  LEFT JOIN vi_product_sales ON vi_product_sales.product_id = products.product_id 
  AND vi_product_sales.category_id = products_categories.category_id 
WHERE 
  1 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND prices_2.price IS NULL 
  AND shared_prices_2.price IS NULL 
  AND products.parent_product_id = 0 
GROUP BY 
  products.product_id 
HAVING 
  sales_discount > 0 
  AND price < list_price 
ORDER BY 
  product asc, 
  products.product_id ASC 
LIMIT 
  0, 20

Query time 0.00437

JSON explain

{
  "query_block": {
    "select_id": 1,
    "having_condition": "sales_discount > 0 and price < products.list_price",
    "filesort": {
      "sort_key": "if(NULL is not null,NULL,descr1.product), products.product_id",
      "temporary_table": {
        "nested_loop": [
          {
            "table": {
              "table_name": "companies",
              "access_type": "system",
              "possible_keys": ["PRIMARY"],
              "rows": 1,
              "filtered": 100
            }
          },
          {
            "table": {
              "table_name": "shared_descr",
              "access_type": "system",
              "possible_keys": ["PRIMARY", "product_id", "company_id"],
              "rows": 0,
              "filtered": 0,
              "const_row_not_found": true
            }
          },
          {
            "table": {
              "table_name": "shared_prices",
              "access_type": "system",
              "possible_keys": [
                "usergroup",
                "product_id",
                "company_id",
                "lower_limit",
                "usergroup_id"
              ],
              "rows": 0,
              "filtered": 0,
              "const_row_not_found": true
            }
          },
          {
            "table": {
              "table_name": "shared_prices_2",
              "access_type": "system",
              "possible_keys": [
                "usergroup",
                "product_id",
                "company_id",
                "lower_limit",
                "usergroup_id"
              ],
              "rows": 0,
              "filtered": 0,
              "const_row_not_found": true
            }
          },
          {
            "table": {
              "table_name": "prices",
              "access_type": "ALL",
              "possible_keys": [
                "usergroup",
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "rows": 262,
              "filtered": 97.32824707,
              "attached_condition": "prices.lower_limit = 1 and prices.usergroup_id in (0,0,1)"
            }
          },
          {
            "table": {
              "table_name": "products",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY", "status", "idx_parent_product_id"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["product_id"],
              "ref": ["devvipiriscom.prices.product_id"],
              "rows": 1,
              "filtered": 90.83862305,
              "attached_condition": "products.parent_product_id = 0 and products.company_id = 1 and (products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A'"
            }
          },
          {
            "table": {
              "table_name": "popularity",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY", "total"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["product_id"],
              "ref": ["devvipiriscom.prices.product_id"],
              "rows": 1,
              "filtered": 100
            }
          },
          {
            "table": {
              "table_name": "prices_2",
              "access_type": "ref",
              "possible_keys": [
                "usergroup",
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "key": "product_id",
              "key_length": "3",
              "used_key_parts": ["product_id"],
              "ref": ["devvipiriscom.prices.product_id"],
              "rows": 1,
              "filtered": 97.32824707,
              "attached_condition": "trigcond(prices_2.price is null) and trigcond(prices_2.lower_limit = 1 and prices_2.price < prices.price and prices_2.usergroup_id in (0,0,1))",
              "not_exists": true
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": ["PRIMARY", "pt"],
              "key": "pt",
              "key_length": "3",
              "used_key_parts": ["product_id"],
              "ref": ["devvipiriscom.prices.product_id"],
              "rows": 1,
              "filtered": 100
            }
          },
          {
            "table": {
              "table_name": "vi_categories",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
              "key": "PRIMARY",
              "key_length": "3",
              "used_key_parts": ["category_id"],
              "ref": ["devvipiriscom.products_categories.category_id"],
              "rows": 1,
              "filtered": 100,
              "attached_condition": "(vi_categories.usergroup_ids = '' or find_in_set(0,vi_categories.usergroup_ids) or find_in_set(1,vi_categories.usergroup_ids)) and vi_categories.`status` in ('A','H') and vi_categories.storefront_id in (0,1)"
            }
          },
          {
            "table": {
              "table_name": "vi_product_features_values",
              "access_type": "ref",
              "possible_keys": [
                "lang_code",
                "product_id",
                "idx_product_feature_variant_id"
              ],
              "key": "idx_product_feature_variant_id",
              "key_length": "3",
              "used_key_parts": ["product_id"],
              "ref": ["devvipiriscom.prices.product_id"],
              "rows": 14,
              "filtered": 12.99212551,
              "attached_condition": "trigcond(vi_product_features_values.lang_code = 'pt')",
              "using_index": true
            }
          },
          {
            "table": {
              "table_name": "descr1",
              "access_type": "eq_ref",
              "possible_keys": ["PRIMARY", "product_id"],
              "key": "PRIMARY",
              "key_length": "9",
              "used_key_parts": ["product_id", "lang_code"],
              "ref": ["devvipiriscom.prices.product_id", "const"],
              "rows": 1,
              "filtered": 100,
              "attached_condition": "trigcond(descr1.lang_code = 'pt')"
            }
          }
        ]
      }
    }
  }
}

Result

product_id product company_name popularity price product_type parent_product_id list_price sales_discount is_shared_product
12 100g Pants CS-Cart 76 30.00000000 P 0 31.00 3.225806 N
148 16GB A Series Walkman Video MP3 CS-Cart 360 130.00000000 P 0 219.00 40.639269 N
5 46" Class (45.9" Diag.) LCD 610 Series TV CS-Cart 333 899.99000000 P 0 1199.99 25.000208 N
23 5.1 Channel Blu-ray 3D Home Theater System CS-Cart 378 599.99000000 P 0 699.99 14.285918 N
1 65" Class (64.5" Diag.) LED 8000 Series Smart TV CS-Cart 486 5399.99000000 P 0 6499.99 16.923103 N
149 8GB E Series Walkman Video MP3 CS-Cart 351 53.99000000 P 0 89.99 40.004445 N
79 adiZero Tempaia Shoes CS-Cart 27 96.00000000 P 0 98.00 2.040816 N
238 Apple iPhone 4S Black CS-Cart 339 499.99000000 P 0 552.00 9.422101 N
239 Apple iPhone 4S White CS-Cart 453 509.99000000 P 0 552.00 7.610507 N
172 Compact Full HD Camcorder CS-Cart 360 299.99000000 P 0 334.00 10.182635 N
167 D3100 + 18-55 VR Lens Kit CS-Cart 357 549.95000000 P 0 599.95 8.334028 N
280 T-shirt, Color: Black CS-Cart 133 36.00000000 P 0 50.00 28.000000 N
282 T-shirt, Color: Blue CS-Cart 500 27.99000000 P 0 75.00 62.680000 N
278 T-shirt, Color: White CS-Cart 72 30.00000000 P 0 75.00 60.000000 N
8 Toshiba 32TL515U 32" Class 1080P 3D LED HD TV CS-Cart 408 849.99000000 P 0 949.99 10.526427 N
150 Wildwood city classic CS-Cart 537 120.00000000 P 0 600.00 80.000000 N
13 Your Idea, Inc. 12 Steps to Building a Million Dollar Business -- Starting Today! CS-Cart 24 11.96000000 P 0 12.00 0.333333 N