Kailh (Kaihua) makes a few switches that have 3 mm travel or 3.5 mm travel as opposed to 4 mm of Cherry MX.
They have been used by various keyboard manufacturers, and rebranded with those manufacturers names.
For instance, there is the SteelSeries QS1 with 3 mm travel, which is found in the SteelSeries Apex M800. The keyboard should not be confused with the non-mechanical keyboard with similar look, and it is a bit expensive.
A rebranded Kailh switch with 3.5 mm travel is found in Tesoro Gram. It is suspected to also be in Hori Edge, but that has not been confirmed yet.
3.5mm key travel is not much different from 4 mm in feel though. Also Alps (and Alps clones) and the Cherry MX "Speed"/"Silver" (Corsair Rapidfire) have ~3.5 mm key travel.
Kailh is supposed to come out with a clone of Cherry ML with comparable key travel but I have not seen any keyboard with it yet.