What's the use of the Mzulft Room Key?

I managed to pick an Expert-level lock while rummaging through Mzulft and found a Mzulft Room Key. What's it used for?

(Note that I'm not talking about the Mzulft Observatory Key, which is part of the quest line for Mzulft.)

Solution 1:

The key unlocks the room you find it in.

Part of the south wall of the room are metal bars, allowing you to see the key on the table. As you can see the key, you can use the telekinesis spell to get the key and avoid having to pick the lock. It's the only use of the key I know. I have just cleared Mzulft and can confirm the Mzulft room key opened the door for me.

Solution 2:

The key unlocks the room you find it in as kenono says. It also unlocks the next room you pass on your right, which is secured with an expert level lock like the room you find the key in.