Have looked 20 times. Hes not there
# 1 May 16, 2014
# 6 May 16, 2014Key Wardens are not intended to show up unless the game is set to Torment difficulty, but they sometimes do because of a bug. I know that didn't answer your question directly, but it's possible they're not showing up due to the difficulty being too low.
Try setting the game to Torment 1 (or higher), and see if you can find them. If they're still not spawning for you then we'd definitely love to hear about it. Thanks, and good hunting!