Utilities are single or multiple-use items that can be used during combat or to complete a variety of tasks.
How to get it?
You can get Golden Key by killing Lich,Ghost King and Skeleton Champion.
Tips
If your inventory is full, you will not receive any new items from the stash, even if the roll is for a desirable item such as a halberd or spear. This is because your inventory is already filled with other items, such as gold.