Many people are still entirely happy with friction front shifters, particularly with set-ups where you have to move your hand to the shifter anyhow. With only a double front, properly adjusted limit screws should allow you to pretty much toggle between end positions and be done with it.
Come to think of it, I don't think I've ever seen a 2-speed front shifter that's indexed unless it's a brifter.
And while I haven't tried it, I don't know if a front brifter intended for 8/9/10-speed rear system would be compatible with your setup. There may be some issues with chain/cage width, and possibly chainring spacing.
Looking at Google image search result, you've got a drop bar bike. This really limits the amount of indexed shifters(apart from brifters) that you can easily use anyhow.
Had it been flat bar, you'd have been able to pick up pretty much any indexed 3x7 front shifter and run with that. Using limit screws to dial out an unused position is no big deal.
You may be able to track down a front indexed thumb shifter for 3 rings, and bodge that one onto your stem or bar. I think I've handled one of those.