I don't. I revealed the key on Humble shortly before creating the giveaway, and I just checked the five giveaways I created to confirm that I didn't accidentally use the same key in two of them (e.g. use 4/5 keys with one duplicated instead of using all 5). However, all 5 have unique keys. So it looks like Humble gave me a key that has already been redeemed! Let me see if I can get them to provide another one, and if not, I hope you'll let me delete this.
I'm sending you a Steam friend request so we can discuss further.

One point of caution - I'm just about to go to bed for the night, and tomorrow after work, I have to go out of town for a bit over a day, so my communication may be a little spotty for a couple days.