Hi @DABRIT 
I added a few functions to the script that you can use to unlock the treasure box in different ways than shooting the lock, including lockpicking it.
You can make the treasure box invincible (with no health), and you can add the lockpick feature in the client.lua file.
I can help you through the setup if you like.
You might like one of my scripts (20% off discount)
Advanced (Realistic) Fishing
Chimp Minigame
Advanced Drone
Live Staff Chat
The Gallow
Auto Vehicles Deleter
Advanced Items Spawner
Special Server Restarter
Advanced Trade & Exchange System