SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a586e278d7db88ddd4ea56df5f5ba133aeb4ad43cadbdee0b8ecf3face8531' 
  AND token = 'AmVpd2dZLsOjEeztFr5lwBKBodzeGemqm/jpTWbvAmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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