There is also a fairly large luggage locker facility on the parking garage level of Gare Oriente.
Find your way down the escalators until you arrive at the level with the internet cafe and cafes/food court.
With the Internet cafe to your right, head past the shops and you will enter the long white passage that leads to the parking, toilets on the left and half way along on the right, a doorway leading to the left luggage lockers.