SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26c471c329878b40548aedeaa288cdf40ebfa6b157b221eeddeb09acdced8b53' 
  AND token = 'esqNYAb/6Er72UbYsaVT6TnYhq7MNEmUbneo5Rc4jQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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