Unpacking a 1Mb gzip file would only be expected to take a second or two.
No need to check phpMyAdmin if it says no more than that.
Two possibilities: 1) the web server kills off PHP for running too long, or 2) there's a problem with the write permissions on the wp-content directory.
I'll add in an extra check for 2). If you were willing, can you share the backup set with me? Then I can test a migration from here, which will go faster. If sharing via Google Drive (like last time), then it's best to set the share to be public for anyone with the URL, and email me the URL at contact@updraftplus.com.
David