waiting for client write

attached is the screenshot of RDS performance insights for AWS and it shows
high waiting client writes. The api performance is slow. I read that this
might be due to IOPS on RDS. However we have 80k IOPS on this test RDS.

Below is the query which is being load tested

SELECT

a.menu_item_id,
a.menu_item_name,
a.menu_item_category_id,
b.menu_item_category_desc,
c.menu_item_variant_id,
c.menu_item_variant_type_id,
c.price,
c.size_id,
c.parent_menu_item_variant_id,
d.menu_item_variant_type_desc,
e.size_desc,
f.currency_code,
a.image,
a.mark_id,
m.mark_name

FROM .menu_item_category AS b, .menu_item_variant AS c,
.menu_item_variant_type AS d, .item_size AS e,
.restaurant AS f,
.menu_item AS a

LEFT OUTER JOIN .mark AS m
ON (a.mark_id = m.mark_id)

WHERE a.menu_item_category_id =
b.menu_item_category_id AND a.menu_item_id = c.menu_item_id AND
c.menu_item_variant_type_id =
d.menu_item_variant_type_id AND d.is_hidden = 'false' AND
c.size_id = e.size_id AND a.restaurant_id =
f.restaurant_id AND f.restaurant_id = 1528 AND
(a.menu_item_category_id = NULL OR NULL IS NULL)

AND c.menu_item_variant_id = (SELECT
min(menu_item_variant_id)
FROM
.menu_item_variant
WHERE menu_item_id
= a.menu_item_id AND deleted = 'N'
LIMIT 1) AND
a.active = 'Y'
AND (CONCAT_WS('', ',', a.hidden_branch_ids,
',') NOT LIKE CONCAT_WS('', '%,4191,%') OR
NULL IS NULL)
AND .is_menu_item_available(a.menu_item_id, 'Y') = 'Y'

ORDER BY a.row_order, menu_item_id;

--Ayub