The current equivalent of a 9590? Luckily, there isn't one.
In a spec, on paper sense, the 9590 is an 8 "core" (debatable), 8 thread chip.
Loosely, a Ryzen5 1400 would be somewhere in the same ballpark - with great improvements in IPC and power draw.
A Ryzen5 1600 or 2600 would be what I'd look to for a modern gaming system with a 1070TI (if you're sticking with AMD). 6c/12t.
Remember, you'll need a new AM4 motherboard & DDR4 (high speed, 3000MHz+) for compatibility with a new chip.
Looking at your current build (shows a 6300, not a 9590?), you're pretty much looking at a new build.
The CX430 isn't great, the MB/RAM won't be reusable.... you can only really keep the HDD and Case.