Here? https://languagelog.ldc.upenn.edu/nll/?p=44941
In Indoeuropean it's only present in the Germanic and Celtic branches (Protogermanic: marhaz, Protoceltic: markos), but in the Far East, as well as Chinese 馬 (mǎ) there's Mongolian морь, Korean 말 (mal), and Japanese うま (uma).
I can't find any Finno-Ugric or Turkic cognates, so it looks like there are two separate clusters.