Finally figured out how to do it:

cfg:
modparam("acc", "db_url", DBURL)
...
modparam("sqlops","sqlcon", CBDBURL)
...
modparam("sqlops","sqlcon", ASGDBURL)

and startup:

kamailio -f /etc/kamailio/kamailio.cfg -E  \
  -A 'DBURL="mysql://admin:mypass@db.mydomaincom/kamailio"' \
  -A "CBDBURL=\"cb=>admin:mypass@db.mydomaincom/kamailio\"" \
  -A 'ASGDBURL=\"asg=>admin:mypass@db.mydomaincom/kamailio\"' -DDDD 2>&1

Now let's try and put that on the startup systemd script.