MySQL Temporary Table with Group By and Group Concat Extremely Slow - mysql

Question

I'm trying to build out a fairly simple temporary table. The table will end up being 2 columns:
1 A product ID
2 A string of concatenated compliance data in a format that can be consumed later
CREATE TEMPORARY TABLE products.compliances_data
(INDEX product_id_idx (product_id))
SELECT
products.product_id,
GROUP_CONCAT(JSON_OBJECT('compliance_code', cc.compliance_code, 'compliance_full_name', pc.full_name, 'compliance_web_description_short', pc.web_description_short) SEPARATOR ' - ') as compliances
FROM products.products products
LEFT OUTER JOIN products.material_compliance_map cc on products.material_id = cc.material_id
LEFT OUTER JOIN products.compliances pc on cc.compliance_id = pc.compliance_id
GROUP BY products.part_number
The table gathers and joins information from 3 tables.
The products table is the main source of information. The products table has a column for material_id.
The material_compiance_map table. This is a many-to-many table that maps material_id's to compliance_id's
The compliances table. This is the table where the actual data is stored that I need to pull from to build out the concatenated object.
The problem is the creation of the temporary table takes 3-4 minutes to run yet only yields about 1.2 million entries which seems incredibly slow.
Running an explain on the select portion of the query yields:
Explain on select image
There are only 642 entries in the material_comliance_map so there's not an awful lot of data here that needs to be traversed.
I've tried removing the group_concat and that seems to speed up the query about 33%. The problem seems to revolve around the group by statement.
How can I improve the speed when building this temp table?
EDIT:
Schemas:
material_compliance_map schema
'material_compliance_map'
CREATE TABLE `material_compliance_map` (
`material_id` int(11) NOT NULL,
`material_code` varchar(20) COLLATE utf8_unicode_ci NOT NULL,
`compliance_id` int(11) NOT NULL,
`compliance_code` varchar(20) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`material_id`,`compliance_id`),
KEY `fk_compliance_id_material_compliances_compliances` (`compliance_id`),
KEY `fk_material_id_material_compliances_materials` (`material_id`),
CONSTRAINT `fk_compliance_id_material_compliances_compliances` FOREIGN KEY (`compliance_id`) REFERENCES `compliances` (`compliance_id`) ON UPDATE CASCADE,
CONSTRAINT `fk_material_id_material_compliances_materials` FOREIGN KEY (`material_id`) REFERENCES `materials` (`material_id`) ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
compliances schema:
'compliances'
CREATE TABLE `compliances` (
`compliance_id` int(11) NOT NULL AUTO_INCREMENT,
`compliance_code` varchar(20) NOT NULL,
`full_name` varchar(155) DEFAULT NULL,
`web_description_short` varchar(45) DEFAULT NULL,
PRIMARY KEY (`compliance_id`),
UNIQUE KEY `compliance_id_UNIQUE` (`compliance_id`),
UNIQUE KEY `compliance_code_UNIQUE` (`compliance_code`)
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=latin1
products schema:
'products'
CREATE TABLE `products` (
`part_number` varchar(27) NOT NULL,
`material_code` varchar(30) DEFAULT NULL,
`material_id` int(11) DEFAULT NULL,
`size_code` varchar(15) DEFAULT NULL,
`size_id` int(11) DEFAULT NULL,
`erp_description_1` varchar(31) DEFAULT NULL,
`erp_description_2` varchar(31) DEFAULT NULL,
`search_description` varchar(250) DEFAULT NULL,
`weight_lbs` decimal(8,4) DEFAULT NULL,
`part_number_prefix` varchar(15) DEFAULT NULL,
`tight_tolerance` tinyint(4) DEFAULT NULL,
`product_id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`product_id`),
UNIQUE KEY `part_number_UNIQUE` (`part_number`),
UNIQUE KEY `product_id_UNIQUE` (`product_id`),
KEY `fk_material_id_products_materials` (`material_id`),
KEY `fk_size_id_products_sizes` (`size_id`),
KEY `product_id` (`product_id`),
KEY `size_id_idx` (`size_id`),
KEY `size_id_productsidx` (`size_id`),
KEY `material_id_idx` (`material_id`),
CONSTRAINT `fk_material_id_products_materials` FOREIGN KEY (`material_id`) REFERENCES `materials` (`material_id`),
CONSTRAINT `fk_size_id_products_sizes` FOREIGN KEY (`size_id`) REFERENCES `sizes` (`size_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1140987 DEFAULT CHARSET=latin1