Can I import a mysql dump to a laravel migration?

You can import dumps in Laravel like this:

DB::unprepared(file_get_contents('full/path/to/dump.sql'));

If I were to refactor an existing app, though, I’d take the time to write migrations from scratch, import the dump into different tables (or a different db, if table names are the same) then import the content to the new structure via seeds.