The first key is up as of 8pm Atlantic and is only valid for 3 hours.
PC Key: WBK3T-TSH6Z-633B3-BT3TT-Z6SR5
XBox 360 Key: C3CBJ-CW5CR-3R6TR-5F33T-5RXZX
PS3 Key: C3CBJ-CW5HJ-6S3WJ-9B53T-5RX6C
I'm working all night tonight so I'll post up the info for the ones released at 1am and 7am. I should be up and about by the time the next one is posted tomorrow afternoon at 1pm, but I might miss the one at 5pm.
Again, all times in this post are Atlantic, while Gearbox uses Central on their Twitter feed.
I reckon a month or so down the road Golden Keys will seem like no big deal though (they kind of do now). If they were the highest tier that might be a bit different. Does make me wonder if Gearbox will update the chest though once everyone starts hitting max level.