Thank you, I now have 3 golden keys currently with no purpose :D
What do you mean with no purpose? Use 'em.
Their only use is for levels 1-20.
NO do not listen to this save them for level 50 much more worth it.
You aren't level 50, if you were you'd know purple ar stupid eas to find. I saved mine til 50 and wasted four keys on weapons I sold withon a day. Use them levels 20-45 so you actually enjoy the guns you get.