SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bb71328505e0ab8acd98c47f0840c1e36adfed18a5bf936fd38313b4f91c5c2' 
  AND token = 'YQeQtZCuxikYv8OtTio7+K8Vq4f8pQS5gLmfPY09mqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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