You can use Salt agentless to run Salt commands on a system without installing a Salt minion. The only requirements on the remote system are SSH and Python.
When running in agentless mode, Salt:
You can use Salt agentless in conjunction with a master-minion environment, or you can manage all of your systems agentless.
This Get Start guide walks you through the essentials of running Salt in agentless mode, and includes a tutorial that shows you how to create a standalone Salt SSH environment.