Enchanted Keys are used to open lockboxes.
They can be bought from the Zen Market each, or 10 keys, 50 keys and VIP 1 month.
As of July 17th, 2014, all existing Enchanted Keys were made bound to account on pickup.
They are also available from a [VIP Account Rewards] pack.
The teeth of the key seem to be ever shifting and can feel a slight pull towards any nearby locks as though it is always searching for its match.