The keel bolts are integral to the keel and should not (can not) be removed. Also do not remove your keel from the hull simply to "check" the keel bolts--you may do more damage than good.

However, they should be inspected and tightened periodically, and the nuts and washers can be renewed.

Refreshing keel bolts involves removing the nuts (one at a time), cleaning the threads and area around threads as best possible. Inspect as you can, add polysulfide underneath the washer and replace the nuts (without lubricant).

Do not overtighten keel bolts--they do not need a cheater bar to tighten. Standard torque specification for 1/2" stainless bolts is 45 ft/lbs, which is not super tight (car lugnuts are generally specified to around 90 ft/lbs). Overtightening is more likely to lead to bolt failure than undertightening.

In the fleet, only one boat has suffered a keel bolt failure. After researching this issue, it seems best to trust your keel bolts but also: never stand under a hoisted boat.