MySQL migration from 5.5 to 5.7 extremely slow - mysql

Question

As mentioned in the title, I'm migrating from 5.5 to 5.7, and I have 1 query that totally broke:
SELECT
COUNT(*) as count,
detections.vendor
FROM (
SELECT id FROM telemetry_user_agents
WHERE date < DATE_SUB(NOW(), INTERVAL 0 DAY)
AND date > DATE_SUB(NOW(), INTERVAL 7 DAY)
) agents
LEFT JOIN telemetry_detections detections on detections.user_id = agents.id
GROUP BY detections.vendor
ORDER BY count DESC
LIMIT 20
On 5.5 the query takes 4 seconds, on 5.7 it takes 400 seconds (!), with exact same indexes and data. I've read about bugs in 5.7, but I'm pretty sure I can find a workaround with some query optimization and/or better indexes.
user_agents has 200k records, detections has 900k records
Here's the structures:
CREATE TABLE `telemetry_user_agents` (
`id` int(11) NOT NULL,
`date` datetime NOT NULL,
`program` text NOT NULL,
`country` text NOT NULL,
`ip` text NOT NULL,
`operating_system` text NOT NULL,
`bits` int(11) NOT NULL,
`version` text NOT NULL,
`license` text NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
ALTER TABLE `telemetry_user_agents`
ADD PRIMARY KEY (`id`),
ADD KEY `date` (`date`) USING BTREE;
ALTER TABLE `telemetry_user_agents`
MODIFY `id` int(11) NOT NULL AUTO_INCREMENT;
CREATE TABLE `telemetry_detections` (
`id` int(11) NOT NULL,
`user_id` int(11) NOT NULL,
`type` text NOT NULL,
`vendor` text NOT NULL,
`name` text NOT NULL,
`value` text NOT NULL,
`hash` text NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
ALTER TABLE `telemetry_detections`
ADD PRIMARY KEY (`id`),
ADD KEY `user_id` (`user_id`);
ALTER TABLE `telemetry_detections`
MODIFY `id` int(11) NOT NULL AUTO_INCREMENT;
And the explains:
5.5
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 95286 Using temporary; Using filesort
1 PRIMARY detections ref user_id user_id 4 agents.id 19
2 DERIVED telemetry_user_agents ALL date NULL NULL NULL 202047 Using where
5.7
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE telemetry_user_agents NULL ALL date NULL NULL NULL 200866 46.50 Using where; Using temporary; Using filesort
1 SIMPLE detections NULL ref user_id user_id 4 adlice_stats.telemetry_user_agents.id 19 100.00 NULL
Any help? :)
EDIT: After I created a bunch of indexes:
5.7:
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE telemetry_user_agents NULL range date,date_2 date_2 5 NULL 131741 100.00 Using where; Using index; Using temporary; Using f...
1 SIMPLE detections NULL ref user_id user_id 4 adlice_stats.telemetry_user_agents.id 19 100.00 NULL