Could not = impossible

Hello everyone

I found this information on "English Page" and I'm wondering whether "could not" in this context can refer also to the future?

Thank you

REMEMBER: "Could not" vs. "Might not"
"Could not" suggests that it is impossible for something to happen. "Might not" suggests you do not know if something happens.

Examples:

Jack might not have the key. Maybe he does not have the key.
Jack could not have the key. It is impossible that he has the key.