Last tested: Aug 9, 2019
It is not possible to do that in Looker at the moment. You can vote for a feature request here: Save a sql runner explore as a look or add to a dashboard.
However, if the look is only accessible by Admins, you can use this workaround (remember, ONLY Admins, other users will get a model not found/some other error).
For this, go to Admin-->Connections-->Explore from the cog. This will take you to a page where you can choose the table/view. That will eventually take you to the explore page (similar to what you would get from sql_runner). Choose your fields in this explore.
You will now see the option to save as look/to dashboard from the cog!!