SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c57f6abd47fb25c7756135a485eeb6d09d92e918cd4cdd7f7509ef125691867' 
  AND token = 'opHtA1kQK8ULP4WgULrKL7Q2BFJhDYLquKPjiRz1kfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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