First, I tried to see if the key could be bypassed. I dropped a drone in the first room of the labyrinth, the one you access after entering the labyrinth via the warp accelerator at its entrance.
The drone was visible and warpable after being probed down by combat scanners. So, I did scan it down, and tried to warp to it. Rather than landing on the grid of the first labyrinth room, I landed on the warp accelerator at the entrance of the labyrinth - regardless of having the key or not having it in my cargo hold. I could not warp to the dropped drone, over 73 thousand km away.
After the drone study, in the first room, I remarked something I had not noticed before. Flares!
On the image above you see the Aphi sun below, the octagonal warp gate complex in the middle, and above: flares. These give bursts of energy, about every ten seconds. Something appears to explode at the base, and a vertical pillar of fire erupts from them, and after the eruption the flare dies down and goes quiet for a couple of seconds, only to repeat the cycle after that. They are not solar flares, as they're clearly disconnected from the sun.
There are more flares than there are labyrinth rooms; I count seventeen of them. They seem to be located on a plane, and they are static - they flare up periodically but always in the same place. Perhaps some of them coincide with the location of other labyrinth rooms? Perhaps they indicate hidden rooms in the labyrinth? I do not know. I will explore.
