Friend figured this out:
Program files>Steam>Steamapps>Common>Borderlands 2>DLC>POPremierclub>Lic>willowDLC.ini
Open up the WilloDLC.ini. You will see brackets that say "goldenkeys." Then next to numkeys, change the value from 1 to whatever you want below 546 (it seems to cap out around there.)
I'm sure they will find out about this and prevent it from working, but if you pre-ordered the game on Steam then might as well do this while you can. The golden keys open up the rare weapon golden chest thing in Sanctuary, and you get purple weapons that scale to your level.