SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa136a46a13dc815be32dfd7f750fd43300988e3a0c314a54677862981f9de88' 
  AND token = '4Z6LcF9cJFh9nmIPYIGDkHcaPSMYKyGD1k8ExuO9q9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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