VoidLock I asked on the Pax Dei Discord and it looks as though the Steam keys will not get sent out to anyone until the release on Steam. So at 7am CST we will all get emailed our keys and will be able to start the download. Unfortunately we will be lagged a little behind getting into the servers. They should have had the Steam release an hour before servers went live so everyone could have had it installed and ready to go.
VoidLock Keys have been distributed at 5am CST, they can be redeemed on Steam ASAP. According to the update the game should be able to be started downloading a little bit before 7am CST. They did say they cannot guarantee this however.