Oh of course. They've already used them. The Kinzhal is a hypersonic missile. The plot twist is, Ukraine is able to intercept them anyway.
Patriot missiles have about a 70% success rate against Kinzhal hypersonics in the war so far.

As for a Sino-Japanese War, that's always possible but I think China will attack the Philippines (which they think will be an easy target) before they try to fight Japan. If China attacks Japan they'll find out fast just how weak the PLA really is.