Are you talking language or are you talking law?
Because language wise it is always momentarily for an action that happens or is or might be happening.
A synonym would be willing. You can't retroactivly be not willing for a thing in the past, were you do in fact were willing. Same as you cannot be willing later for a thing you were unwilling at the time.
It is not called changing your consent, there are other words for that. The first would be regret, the second approval. You can change your willingness during the act, though.
As for a wife kissing her husband, assuming a normal marriage, the wife would know the consentual status of the husband about kissing.
And while being high might impair your legal and attractivness judgment, if you screw while high and not while incapacitated, you were obviously willing and thus consenting.
You might regret it. That is even a common trope in story telling, drunkenly waking up next to a stranger. Or you might approve and go for round two in the morning.
But you cannot change your past consent. Unless you were roofied, you willingly got high with a potential sexual partner. One of the reasons to actually get high is to lower inhibitions. Imho it is a lame excuse to claim one could not give consent to whatever happens. If you get high willingly, you have to accept the consequences as your doing.
Now, legally, there might be differences, as legal terms have nothing to do with everyday language and are specific for a jurisdition and not universal. Language I can put into a translator, laws not so much.