Although it doesn't say so anywhere on it, I believe this may well be the model called an Explosif Pro in the 1992 catalogue. I don't know how much more they cost than the standard Explosif, but they came with a custom paint job in any Imron colour you nominated (although in fact yours is the third that I've seen in that nice shade of green). The catalogue also says they came with a Suntour XC Pro groupset, but yours seems to have the Deore DX of the standard Explosif, which was an option for the Pro.
The braze-on seat clamp makes it look as though it is a 1991 frame, as 1992 frames had removable clamps, but every 1992 Explosif Pro that I have seen has the 1991 clamp. It seems possible that the Explosif Pro frames were a batch of 1991 Explosifs left over from that model year. It doesn't make much difference either way, as the tubesets were the same in each year, Tange Prestige Concept with the tapered and ovalised top and down tubes.
However we might be able to tell for sure if you give us the serial number of the frame (on the bottom bracket shell) and the lengths of the seat tube (centre of bb to top of seat tube), top tube (c-c) and head tube (i.e., the geometry changed slightly between 91 and 92)
The other extraordinary thing about your bike is that it has a Track Two fork, which isn't mentioned in the 1992 catalogue and I didn't know it was available in 1992. Indeed although it is in the 1991 catalogue, I have never seen even a 1991 Kona with a Track Two fork either, let alone a 92 - only 1990 Explosifs. In that respect, the bike is certainly very rare if not unique.
It must be very unusual for there to be a NOS 1992 bike, but I guess it is quite a nice colour to have as an ornament around the shop all that time!