"What's - " but he spots it before he can finish the question, the shiny material on the floor. "Oh! It must be the key. I had to use one to get us in the room I was in - here, I've gotta put you down to pick it up, and we'll see if it works okay?"

Which is why the little one is carefully placed down on the ground, so the card can be picked up, and swiped.