Error: Error executing query

The software returned the following error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '&& password = "d41d8cd98f00b204e9800998ecf8427e"' at line 1

Query Executed: SELECT * FROM tsl_users WHERE username = && password = "d41d8cd98f00b204e9800998ecf8427e"