Drop In Aftercare - is this a thing?

Hi! I'm wondering if there are any affordable afterschool programs for elementary students that operate on a drop-in basis in Oakland or Berkeley. My OUSD 1st grader is usually picked up by parents or grandparents, but sometimes we have issues last minute when there isn't a family member available to be with him for the afternoon. We often don't know until that morning or the night before that this will be the case. Does this type of thing exist? Thanks!