1) You can run this query
Code:
ALTER TABLE xcart_orders DROP INDEX userid, ADD INDEX us (userid, status), ADD INDEX es (email(64), status);
This change is optional.
2) This is the correct syntax
http://dev.mysql.com/doc/refman/5.1/en/create-table.html
us is the key name. It is formed as an acronym for the
Userid
Status phrase.