SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5b49921ca11efaa61bab92f837546ede3852b750a3fdbffe480221df96992c0' 
  AND token = '9ML+mQRrJS9c0zrSBgWXZ9huu7bIAxnE3IOYVgBKVkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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