280 ms is poor (that’s almost 1/3 a second!) easiest way to improve is to use an ethernet cord. Looking into what your ISP provides could be beneficial as well.
Considering you're in Singapore, and there's a pretty big ocean + a heck of a lot of land in between, I'd say this is sort of an expected high ping. Being on wired internet may improve things a little bit. But it's going to be fairly high all the time.
280 ms is poor (that’s almost 1/3 a second!) easiest way to improve is to use an ethernet cord. Looking into what your ISP provides could be beneficial as well.