You wait until the Lucario isn't looking then approach the cart quietly. Good, he isn't looking you think.
However, if you wanted to be a thief, you shouldn't have tried it on a Lucario. The Lucario could sense your aura. As you reach the top of the cart, you are eye to eye with its owner. Before you know it, you are punched square in the face and knocked out.
Lucarios have a sense of justice so this one had no problems making a meal out of a thief. Your unconscious body was quickly gulped down. "Mmm" the Lucario said as he patted his belly and returned to work. You were nothing but nutrients for the hard working body of the Lucario.
