SELECT subkey, value FROM plist WHERE path='/Library/Preferences/SystemConfiguration/preferences.plist' AND key='NetworkServices' AND subkey like '%HTTP%P%' AND value != '';

+---------------------------------------------------------+---------+
| subkey                                                  | value   |
+---------------------------------------------------------+---------+
| Proxies/HTTPPort                                        | 5555    |
| Proxies/HTTPSProxy                                      | 1.1.1.1 |
| Proxies/HTTPSPort                                       | 5555    |
| Proxies/HTTPProxy                                       | 1.1.1.1 |
+---------------------------------------------------------+---------+

SELECT DISTINCT p.pid, x.name, x.cmdline, p.local_port FROM process_open_sockets as p JOIN plist as l ON p.local_port=l.value JOIN processes as x ON p.pid=x.pid WHERE l.path='/Library/Preferences/SystemConfiguration/preferences.plist' AND l.key='NetworkServices' AND l.subkey like '%HTTP%Port' AND l.value != '';

+-------+------+------------+------------+
| pid   | name | cmdline    | local_port |
+-------+------+------------+------------+
| 19821 | nc   | nc -l 5555 | 5555       |
+-------+------+------------+------------+

plist

kolide_plist