You can just capture the output and pass it through a filter, something like:
mysql show processlist
| grep -v '^\+\-\-'
| grep -v '^| Id'
| sort -n -k12
The two greps strip out the header and trailer lines (others may be needed if there are other lines not containing useful information) and the sort is done based on the numeric field number 12 (I think that's right).
This one works for your immediate output:
mysql show processlist
| grep -v '^\+\-\-'
| grep -v '^| Id'
| grep -v '^[0-9][0-9]* rows in set '
| grep -v '^ '
| sort -n -k12