Please post output of these commands:
SHOW TABLE STATUS LIKE 'tablename' - for all your 4 tables
SHOW CREATE TABLE tablename - for all your 4 tables
Please surround these outputs with code tags - [ code ] + [/ code ]
thanks to code tags your post will be more readable, like this (with code tags)
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
| 1 | SIMPLE | ww | ALL | fk_workerwork_workerid | NULL | NULL | NULL | 3 | |
| 1 | SIMPLE | w | ALL | PRIMARY | NULL | NULL | NULL | 3 | Using where; Using join buffer (Block Nested Loop) |
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
and not like this (without code tags):
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
| 1 | SIMPLE | ww | ALL | fk_workerwork_workerid | NULL | NULL | NULL | 3 | |
| 1 | SIMPLE | w | ALL | PRIMARY | NULL | NULL | NULL | 3 | Using where; Using join buffer (Block Nested Loop) |
+----+-------------+-------+------+------------------------+------+---------+------+------+----------------------------------------------------+
Please explain which exactly query do you want to optimize ?
I see three queries, but only one explain plan, and I am not sure.