MySQL Get rows that only exist in one table performance - mysql

Question

The basics of this query have been asked, and answered, many times before, but I'm still having trouble with performance. Here are the details:
I have the table, Products, that has 105724 rows.
I have an update table, _e360products, that has 51813 rows.
I am matching on an alphanumeric 10 character code, that is indexed (unique) on both tables.
I have tried:
SELECT _e360products.Product_Code, products.StockCode
FROM _e360products Left Join Products ON _e360products.Product_Code = Products.StockCode
WHERE products.StockCode IS NULL
and:
SELECT Product_Code
FROM _e360products
WHERE Product_code NOT IN (SELECT StockCode FROM Products)
and, just for a laugh, even:
SELECT Product_Code
FROM _e360products
WHERE (SELECT count(*) FROM Products WHERE StockCode = Product_code) = 0
None of these have returned results within 20 mins!
If I reverse the queries, i.e. getting unique rows from _e360products, I get results very quickly.
Does anyone have any ideas?
~~~~~ Update ~~~~~
Explain results are:
+----+-------------+---------------+--------+---------------+--------------+---------+------------------------------------------+-------+--------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+---------------+--------+---------------+--------------+---------+------------------------------------------+-------+--------------------------------------+
| 1 | SIMPLE | _e360products | index | NULL | Product_code | 12 | NULL | 50811 | Using index |
| 1 | SIMPLE | Products | eq_ref | stockcode | stockcode | 12 | plumbase_bkup._e360products.Product_code | 1 | Using where; Using index; Not exists |
+----+-------------+---------------+--------+---------------+--------------+---------+------------------------------------------+-------+--------------------------------------+
CREATE TABLE `_e360products` (
`Product_code` varchar(10) CHARACTER SET latin1 NOT NULL DEFAULT '',
`Manufacturers_code` varchar(255) DEFAULT '',
`Description` varchar(255) DEFAULT '',
`Supplier` varchar(255) DEFAULT '',
`Price` varchar(20) DEFAULT '',
`VAT` varchar(20) DEFAULT '',
`Analysis_code` varchar(20) DEFAULT NULL,
PRIMARY KEY (`Product_code`),
KEY `Product_code` (`Product_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `products` (
`productid` int(11) NOT NULL AUTO_INCREMENT,
`QPUM2` varchar(50) NOT NULL DEFAULT '1',
`NWID` varchar(50) NOT NULL DEFAULT '0',
`NHEI` varchar(50) NOT NULL DEFAULT '0',
`NLEN` varchar(50) NOT NULL DEFAULT '0',
`donotdisplayprice` tinyint(2) DEFAULT '0',
`productname` text,
`stockcode` varchar(10) NOT NULL DEFAULT '',
`analysiscode` varchar(50) DEFAULT '',
`usestockcontrol` int(11) DEFAULT '0',
`stockvalue` int(11) DEFAULT '0',
`stock_notification_level` int(11) DEFAULT '0',
`sectionid` int(11) DEFAULT '0',
`productprice` varchar(50) DEFAULT '',
`productprice_incvat` varchar(50) DEFAULT '',
`deleted` int(11) DEFAULT '0',
PRIMARY KEY (`productid`),
UNIQUE KEY `stockcode` (`stockcode`) USING BTREE,
KEY `deleted` (`deleted`),
KEY `allowordering` (`allowordering`),
) ENGINE=MyISAM AUTO_INCREMENT=147440 DEFAULT CHARSET=latin1;
NoteL Products table doesn't include ALL the fields, as there are quite a few...

Answer 1

Please provide a query execution plan (EXPLAIN), it seems your index is not used. Also show as CREATE TABLEs for both tables.

Answer 2

Typo? StockCode[add space here]IS
SELECT _e360products.Product_Code, products.StockCode
FROM _e360products Left Join Products ON _e360products.Product_Code = Products.StockCode
WHERE products.StockCode IS NULL