SELECT 
  vi_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      vi_products_categories.link_type = "M", 
      CONCAT(
        vi_products_categories.category_id, 
        "M"
      ), 
      vi_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  vi_products_categories 
  INNER JOIN vi_categories ON vi_categories.category_id = vi_products_categories.category_id 
  AND vi_categories.storefront_id IN (0, 1) 
  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') 
  LEFT JOIN vi_products_categories AS product_position_source ON vi_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 234 
WHERE 
  vi_products_categories.product_id IN (
    245, 238, 239, 74, 73, 71, 75, 72, 70, 76, 
    67, 86, 106, 105, 101, 69, 125, 120, 117, 
    113, 68
  ) 
GROUP BY 
  vi_products_categories.product_id

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "vi_products_categories",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 23,
          "filtered": 100,
          "index_condition": "vi_products_categories.product_id in (245,238,239,74,73,71,75,72,70,76,67,86,106,105,101,69,125,120,117,113,68)"
        }
      },
      {
        "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.vi_products_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "vi_categories.storefront_id in (0,1) 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')"
        }
      },
      {
        "table": {
          "table_name": "product_position_source",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "PRIMARY",
          "key_length": "6",
          "used_key_parts": ["category_id", "product_id"],
          "ref": ["const", "devvipiriscom.vi_products_categories.product_id"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}