Most any chronograph will work indoors as long as you have good non-fluorescent overhead light. I believe the "Chrony" can be bought with optional incandescent lamps that clamp to it. The problem is getting even lighting over both (or all) of the sensors. Another challenge is finding an indoor range that will let you set up a chronograph. None of the ones around here will let you do that because they won't let you go ahead of the firing line or shoot from significantly behind the firing line. (I agree with that policy for safety.)
If at all possible, do your chronographing outdoors under even light. Quirks in lighting are the leading cause of frustration with chronographs.