SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cba341256b77633b3f69c77526c2c72a999de4470223b7d30df66de3983b07b0' 
  AND token = '4wVy9+OLKCahmKF7XLqw2MJB/YLHK9ZYvzZU7zue3Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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