The key is in the room where you defeat the teddy bear! ;)
Viewing post in Price of Greed jam comments
I found the key no problem but just wanted to note here also that I didn't run into any teddy bears. I was wondering about that when it was mentioned again at the end, I was trying to be thorough but thought I must have missed something, wasn't sure. Either way, I enjoyed myself and I would definitely play more. 👍