”Can I ask you a question?” obviously isn’t that literal, but more of a shorthand for ”do you have the time, energy and inclination to have a discussion with me

”Can I ask you a question?” obviously isn’t that literal, but more of a shorthand for ”do you have the time, energy and inclination to have a discussion with me right now to figure out the answer to a question I have?”. I personally try to ask the question straight away, with some caveats and pleasantries added if needed to avoid friction and stressing people out, but I do think it’s fair enough to do it like above as well. You show that you’re respecting the other person’s time by not dragging them too far into a conversation before they’ve agreed to have it, and you don’t have to write out the full question right then and there if it turns out the person is not available for it at the moment.