Update your BIOS if you haven't already, then get an i5-7400 or -7500 (7600K only if you got the cash for an additional CPU heatsink). You'll want to add another 4GB of RAM (assuming you have 1x4GB) or even replace it and get 2x8GB asap, as that will probably limit your performance heavily.
Going from Skylake and H110 chipset down to Ivy Bridge is just a waste of money, as future upgrades are going to be close to impossible on the 1155 socket platform.
Going for a modern i5 is going to last much longer, and you might even be able to upgrade to Coffee Lake CPUs in the future, without the need of replacing mobo & RAM again.