A programmable locking assembly for an insulated enclosure such as a food delivery box that can be unlocked by the recipient of the box, by pressing a number code on the keypad of the lock, causing a locking finger to slide out from a zipper pull on the lid of the insulated enclosure to allow the recipient unzip the lid to have access to the contents of the enclosure, thereby preventing the food delivery person to access the contents of the enclosure while in route to making the delivery. The number code is texted to the recipient from the sender of the enclosure. In an alternate embodiment, an audio tone can open the lock without the user needing to press numbers on the keypad.