Keirin frames have adopted various rear hub dimensions that were in use elsewhere, and settled down first on 110, then added 120, which since has become the general standard. There were lots of track hub standards so I can't assure you that your frame has the same 110 mm standard that keirin adopted, but the odds are pretty good. The only other 110 mm hub standards I've ever seen have had round 8 mm axles (which predictably tended to bend, which led to their being modified to the flatted 10 mm variety). Even if your frame was built to that round 8 mm standard, it would fit 110 mm flatted axles just fine. Again, unless you have a frame of significant historical value, you might be better off just filing it out to 10 mm spacing and using a modern hub. The only other item I can't be sure of is your frame chain line -- the 8 mm round axles were used on hubs that had slightly different flange spacing, but I don't know whether the cog would actually have a different position in terms of chain line. Check your chainring offset against the chain line numbers on John Dacey's website and if you have standard alignment, you should be fine; if not, a spacer in the bottom bracket can probably solve the problem quickly and easily as well.