SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27fc03fd83e1c36a041957d3742f7300fc5773238fd69a4f0d4a55b5ce2a6bbd' 
  AND token = 'HM1huSjjKZJYsb86aYuTGuW73T6BKZn4IXWZCcUhvWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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