It's not too clear exactly what type of locking skewers you are using, since 'forte'' is just a performance brand name and I dunno what design they are rebranding....

if your lost key is a simple allen with pin in center, a triangle, or a pentagon, just go to a good LBS, they tend to keep a few handy.

if your key is 'unique' such as PinHead skewers, then a sharp flathead screwdriver and a hammer against one of the dimples in the head can gradually unscrew it.

if the above ideas don't apply/work,
get a pair of cone wrenches 2x15mm for the front wheel, 2x 17mm for the back wheel; use them to overtighten the hub bearings, (this will be take muscle since you will be overpowering the cone/locknut friction interface)
overtightening will reduce the OLD(over locknut dimension) of the hub by a few mm; thus relieving the skewer tension so you can unscrew the skewers by hand and drop the wheels out of the frame
afterwards you will need to readjust the hub bearings
(this method defeats every locking skewer ive seen on market)

and of course, as stated already there are destructive removal options
via grinding/dremeling a gripable surface onto the locking nuts, cutting off, etc