Jeweled Lockpick

Jeweled Lockpick is a key that can be crafted and used by jewelcrafters to open locked doors, chests, and lockboxes requiring up to 750 lockpicking skill. As of  Legion, it can open all locks in the game.

Source
This item is created with jewelcrafting (1); its recipe, Design: Jeweled Lockpick, is automatically learned as a quest reward from Hidden Intentions.