If you want to run a single line of SQL, you can pass it as the second argument to the sqlite3 command:
sqlite3 customer.db 'select * from tbl1 where id=25'
See Section 21 of the SQLite command line documentation.
If you have more complex SQL commands to run, you can write an SQL script and pass it in using shell redirection:
sqlite3 customer.db < script.sql
There are other ways to do this.
You can do either of these in Keyboard Maestro within an Execute a Shell Script step.