Why does this simple select by primary key show such intensive CPU usage? I have advanced performance metrics enabled for my m6g.xlarge MySQL instance in RDS.  I'm noticing that the during CPU spikes (which are expected given our app), that it seems a simple query is occupying the most CPU.
The blue query is:
SELECT * FROM `job_batches` WHERE `id` = &quot;91b0f7a8-0693-4cb4-8647-e7509318fbbc&quot; LIMIT 1 FOR UPDATE


I did an explain thinking that might shed some light on it, but the explain looks fine/efficient to me.

Am I correct in my understanding that this simple query is what's driving a good amount of our CPU usage?.  From a query volume perspective, I would expect to see the same number of SELECT * FROM job_batches... queries as I would say the orange SELECT * FROM channel_subscription.  This makes the blue stand out to me as an area of potential optimization.
The table's architecture is:
CREATE TABLE `job_batches` (
  `id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
  `total_jobs` int(11) NOT NULL,
  `pending_jobs` int(11) NOT NULL,
  `failed_jobs` int(11) NOT NULL,
  `failed_job_ids` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
  `options` text CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci,
  `cancelled_at` int(11) DEFAULT NULL,
  `created_at` int(11) NOT NULL,
  `finished_at` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
A possible explanation:

The table is nearly as big as innodb_buffer_pool_size.
The Could did some sort of maintenance just before that spike, hence the buffer_pool (cache) was lost.
UUIDs are terribly inefficient because of how random they are.
Each SELECT (during the spike) found the desired row to not be cached, so it had to read from disk.  (Was there also a spike in I/O?)

If the table is growing is size, the problem will become noticeably worse when the table becomes bigger than the buffer_pool.