Laravel 7x fix race conditions – table cache_locks is empty

I’m trying to fix race conditions by applying Atomic Locks, like stated in the docs: https://laravel.com/docs/7.x/cache

My environment file is configured to use the database driver and I have both cache and cache_locks table migrated.

I can see some contents being written in the cache table but the cache_locks is always empty.

This is my code logic to fix race conditions:

$lock = Cache::lock("{$myUniqueId}_lock", 5);

try 
{
    $lock->block(5);

    // Perform some database operation
    DB::statement("UPDATE my_table SET some_column = {$some_data}");
} 
catch (LockTimeoutException $e) 
{
    throw new Exception('Error with atomic locks');
} 
finally 
{
    $lock->release();
}

While performing a stress test on postman with 20 virtual users:

1. I get the MySQL error Integrity constraint violation: 1062 Duplicate entry '....' for key '....', meaning the locks are not being performed correctly
2. The table cache_locks is always empty, it doesn’t hold any value, I keep refreshing but I don’t see anything being written there
3. The LockTimeoutException is never thrown

What am I missing?