SELECT 
  1 
FROM 
  vi_lock_keys 
WHERE 
  key_id = '51eb70c8ea21167245f24af75e01aeffa73892247853d87365cc9e3959116022' 
  AND token = '+AGwiDdURNAocCuPbI9IpmiQxPXNqLShXnIv0gzkb0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00007

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}