A quality older psu will not "explode"
But, modern power supplied can support the lower power sleep states of modern motherboards.
From that point of view, you can use it.
I might add, that I think your build list is not optimal, depending on your intended usage.
For multithreaded batch apps, the 3600 with 12 threads is excellent.
For gaming where fewer threads are needed, not so much.
For gaming, the graphics card is most important.
Budget 2x the cost of the processor for the graphics card.
If you have aspirations to game at 1440P, then the graphics card becomes even more important.
Here you have a $200 processor and a $160 graphics card.
Do not buy last gen parts if you are buying new.
Look for a 5xx based motherboard.
Ryzen is tightly tied to ram for performance.
3200 speed is a bit slow. Look for 3600.
You could buy a $110 I3-10100 with 8 threads, A $75 lga1200 motherboard and be able to spend some $300 on a much stronger card like a 5600XT, RTX2060 , GTX1660ti or such.
I3 no longer means what it used to.
Here is a review of the i3-10100 which includes comparisons to the 3600 and others:
https://www.techpowerup.com/review/intel-core-i3-10100/16.html