I am trying to obtain the key value of an field after a MySQL insert command in Nintex Cloud

For example, I might run a mysql command INSERT INTO mytable (firstname,lastname) VALUES('John','Doe') and mytable contains the columns ID, firstname, lastname. Where ID is an autoincremented, key field.   

How can I reliably retrieve the value of ID for this insert command?

I cannot run a separate SELECT last_insert_id() command because Nintex connects different instances of the workflow with the same connection. I have tried this and it resulted in duplicate keys.