The H81 chipset does not support cpu overclocking.
Past that, for whatever reason, I do not see a I5-4460 as a supported cpu for your motherboard; likely just a documentation glitch:
https://us.msi.com/Motherboard/support/H81M-P33#support-cpu
The I5-4460 has 4 threads and a passmark rating of 4953 when all 4 threads are fully utilized. The single thread rating is 1871.
Your strongest upgrade would be i7-4770K which sells for $110 or so on ebay.
It has 8 threads and a rating of 7148/2142.
Past that, you are looking at not only a modern cpu but also a new motherboard and ddr4 ram.