You are on right path.
The reason you are not finding the config path web/secure/use_in_adminhtml
in the table is because it was never set in admin.
Only values that are adjusted, or have values saved will get set in the table.
If they don't exist, the defaults will be used. Defaults can either exist from code, or via the respective module's config.xml in the <defaults>
tag (or via the config.xml/local.xml in the etc folder as well)
Since you are using a ssl url, you would want to set the value to 1, not 0 (which is the default)
So, to solve you issue, you have two options:
a. Manually insert the entry for web/secure/use_in_adminhtml into your core_config_data table
The following SQL will do that for you:
INSERT INTO core_config_data (scope,scope_id,path,value) VALUES ('default',0,'web/secure/use_in_adminhtml',1);
b. Change the url in the table back to http://your.domain.com/ (remember the end slash)
In either case, clear the cache (manually by deleting /var/cache)
You should now be able to get back to admin.
You need to change.
In the same tab check Offloader header
value is SSL_OFFLOADED
If you want to use ssl for all pages, then need to change Base unsecure Url
Best Answer
If you want to disable secure url for admin, you need to set the path
web/secure/use_in_adminhtml
value to 0 (or delete the record).