SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fedacc4ad1972421deebccc53dbf73204ac579afaf30773efd6457e3fe4e687' 
  AND token = 'gXqfveKxYvEREHNxkgU4Q6hJh7Kt8JEU2t/Rc3sv0X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}