SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '218a619741d23d9ccc51585311ee055884f844ac2a3ec7dd39f5966eacf9fff9' 
  AND token = 'gOXUl/a8gzP+yccMllZRxRO84Is8PjRIu8hpsnpki0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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