Spraying canned air is not going to drop temperature to -60C, you would need to spray liquid oxygen or other light liquefied gas to go anywhere near that low.
So I'd go with the bogus sensor data or software reporting theory.
You can easily determine whether this is a software or hardware problem by checking BIOS temperatures. If the BIOS reports sane values, the problem is most likely software. If the BIOS also reports bogus values, the problem is most likely hardware.
Those look like standard idle temps for the Intel® Core™ i5-2500K with the stock cooler. Run Prime95 or IBT (Intel Burn Test) on it and see how the temperatures do under load but I guess that you are in good shape.