SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f904d6120650070ab5aa28ca0d743b72833f505d9e2bf6653e26ac3cf8ee53c2' 
  AND token = 't63dtKc3FlUUvVgGknhZ4pPsyLt7r4sslhGQ2VZ0o0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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