SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2c590a827c8a4d81a5ee800e5e4d710469e559dcf024de3111e4503d01817aa' 
  AND token = 'MqCf9orZJ6HoIGE+2fZ4lyb8qzElpHp/9WEARQfLgcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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