Modern OEM cables last very well. They don't need lube as they run in a Teflon tube internally. Lubing ruins them. But you DO lube the connector where in fits into your clutch lever, and at the other end at the actuator arm.

Some bikes wear out cables prematurely but most Japanese bikes do not. If some bright bulb has replaced your original factory cable with a CRAP after market one, then you could have trouble. I would ONLY go with Honda genuine cables.

Not a bad idea to replace your clutch cable NOW. I would not bother carrying a spare at all. After all ... your original cable has lasted 35K kms. The new one should go that distance too. So leave your old cable home, you may want it some time in future ... or give it to a friend.

As mentioned, throttle cable usually last better than clutch. But pull the tank and inspect cables best you can where they connect to carb. Should be clean, kink free with NO binding and no fraying. (if routed correctly) If any of this present, replace. The twist grip end can be a bit tricky to replace on some bikes but usually simple. If the rubber boots around the throttle cables at the twist grip are in good condition and throttle action is easy and smooth, you're probably OK.

As mentioned, worn cables get harder to operate, but you may not notice the change. It's subtle. If you have a chance, try a BRAND NEW version of your bike. Try throttle and clutch. Now try yours. Clutch cables get a bit hard to pull when worn. This caused by repeated use over years, water and dirt ingress.