mysql select中子查询中使用强制索引的优化案例

1，朋友找我帮忙看下比拟慢的sql语句

SELECT
    pg.product_goods_id,
    pg.product_id,
    pg.pdt_code,
    pg.pdt_name,
    pg.brand_name,
    pg.reference_price,
    pg.deposit,
    pg.sale_status,
    pg.is_delete,
    pg.create_date,
    pg.create_operator,
    pg.update_date,
    pg.update_operator,
    si.shop_id,
    si.shop_name,
    pg.goods_img_url,
    pg.is_bargain,
    pg.qr_code_url,
    (
        SELECT
            COUNT(*)
        FROM
            product_attention pa
        WHERE
            pa.product_goods_id = pg.product_goods_id
        AND `status` = 0
    ) AS laud,
    pc.category_name,
    pg.is_experience,
    pg.deposit,
    pg.buy_type,
    pg.content,
    pg.assure_flag,
    pg.market_price,
    pg.qty_cnt,
    pg.sales_cnt
FROM
    product_goods pg 
LEFT JOIN shop_info si ON si.shop_id = pg.shop_id
LEFT JOIN product_category pc ON pc.category_id = pg.category_id
WHERE
    si.market_id IN (1, 2, 3, 12, 13) 
 ORDER BY pg.update_date DESC , pg.product_goods_id DESC
LIMIT 0,
 20;
SELECT
    pg.product_goods_