SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd068c04a46a4d8625a5b91be9be1d31b4dc4afb1cd9be55d25865f57143b7a9e' 
  AND token = 'aCoGsk0k8qjfQtavnm0ciCwKJQvlk81TO71uKFWg3K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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