Thank you.
In the end, I did the following queries because I not only did I want to know if the extensions were used but also if they were actively used. Only extensions in active campaigns or active ad groups were of interest to me.
Also, I wanted to know only about 'ENABLED' extensions and not any of these statuses: PAUSED, REMOVED, UNKNOWN, UNSPECIFIED
SELECT
asset.id,
customer_asset.status
FROM customer_asset
WHERE
asset.id = 1234567890
AND customer_asset.status = 'ENABLED'
---------------------------------
SELECT
asset.id,
campaign_asset.status,
campaign.status,
ad_group.status
FROM campaign_asset
WHERE
asset.id = 1234567890
AND campaign_asset.status = 'ENABLED'
AND campaign.status = 'ENABLED'
AND ad_group.status = 'ENABLED'
---------------------------------
SELECT
asset.id,
ad_group_asset.status,
campaign.status,
ad_group.status
FROM ad_group_asset
WHERE
asset.id = 1234567890
AND ad_group_asset.status = 'ENABLED'
AND campaign.status = 'ENABLED'
AND ad_group.status = 'ENABLED'
---------------------------------