SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9bdca9f775b2798a9601e98560378038f89bf8b88ae74699b25223a8761d6b1' 
  AND token = 'g3H6dUAq9+WAJ7dsCvUE+/eUFjHQMmGpOWrMIWYyQpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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