Yes, Keywin 5 is supported by Windows 10 and all the newest service packs that are available today.
Keywin 5 is supported by all Windows version as far back as Windows XP - but beware that for older Windows versions you need to run older versions of Keywin 5 and by association older firmware by the cabinets.
One should be aware that older Windows OS versions are no longer supported by Microsoft, and that newer cabinet versions demand that you run Keywin 5 version 2.2.0.0 so in some cases when installing new cabinets an new OS might need to be installed, and even a new computer in some cases in order to run the newer OS.