Equivalent to a 5600 and B550 would be B660/B760 and a 12400/12400F (no graphics), but hard to recommend this Intel socket when 13th-14th gen CPUs have degradation question mark, which would make upgrading to a second hand CPU later very risky. That said, a 12400/12400F and H610 board (very basic, but functional) can be a cheap bundle if you shop around, or are prepared to buy a used one.
The newer socket is 1851 (Core Ultra), but that uses DDR5 so not viable anyway.
A 12400 gets close to a 5600 with DDR5. Not to mention an AM5 7400-7500 build will pan any budget Intel build into next week and offers Zen6 support.