SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.youtube_link, products.youtube_link
  ) AS youtube_link, 
  cscart_aval_statuses_descr.descr as aval_descr 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'en' 
  LEFT JOIN cscart_aval_statuses ON cscart_aval_statuses.aval_status_id = products.aval_status 
  LEFT JOIN cscart_aval_statuses_descr ON cscart_aval_statuses.aval_status_id = cscart_aval_statuses_descr.aval_status_id 
  AND cscart_aval_statuses.status = 'A' 
  AND cscart_aval_statuses_descr.lang_code = 'en' 
  LEFT JOIN cscart_product_popularity as popularity ON popularity.product_id = products.product_id 
WHERE 
  1 
  AND cscart_categories.category_id IN (
    412, 898, 897, 899, 461, 900, 468, 432, 
    482, 890, 937, 922, 925, 929, 938, 939, 
    940, 941, 942, 943, 944, 945, 946, 947, 
    974, 975, 976, 977, 978, 979, 980, 981, 
    982, 983, 984, 985
  ) 
  AND cscart_categories.company_id = 1 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
GROUP BY 
  products.product_id 
ORDER BY 
  popularity.total desc, 
  product_id ASC 
LIMIT 
  96, 12

Query time 0.03879

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE products ref PRIMARY,status,product_id_idx,status_idx status 3 const 594 Using index condition; Using where; Using temporary; Using filesort
1 SIMPLE prices ref usergroup,product_id,lower_limit,usergroup_id usergroup 3 mahm3t_cs443.products.product_id 1 Using where; Using index
1 SIMPLE shared_descr eq_ref PRIMARY,product_id,company_id PRIMARY 13 mahm3t_cs443.products.product_id,const,const 1 Using where
1 SIMPLE cscart_aval_statuses eq_ref PRIMARY PRIMARY 4 mahm3t_cs443.products.aval_status 1
1 SIMPLE cscart_aval_statuses_descr ref aval_status_id aval_status_id 10 mahm3t_cs443.cscart_aval_statuses.aval_status_id,const 1 Using where
1 SIMPLE popularity eq_ref PRIMARY,total PRIMARY 3 mahm3t_cs443.products.product_id 1
1 SIMPLE descr1 eq_ref PRIMARY,product_id PRIMARY 9 mahm3t_cs443.products.product_id,const 1 Using where
1 SIMPLE products_categories ref PRIMARY,pt,product_id_idx,category_id_idx,product_category_idx,category_product_idx product_category_idx 3 mahm3t_cs443.products.product_id 3 Using index
1 SIMPLE cscart_categories eq_ref PRIMARY,c_status,p_category_id,idx_category_id PRIMARY 3 mahm3t_cs443.products_categories.category_id 1 Using index condition; Using where

Result

product_id product youtube_link aval_descr
10163 FAKRO FTT/U U6 | white-finished pine window for passive houses
704 Fakro XDP - air permeable underfelt collar <p> Ships within 6-10 business days after receipt of your payment</p>
8894 VELUX GPU 0066 | everfinish, top hung roof window with safe 3-glazing
10212 VELUX GGL 3068 | wooden, pivot roof window with safe 3-glazing
8885 VELUX GGU 0066 | everfinish, pivot window with easy to clean, safe 3-glazing
8893 VELUX GPU 0062 | everfinish, top hung roof window with safe 3-glazing
9966 FAKRO Window lock ZBL <p style="color: #1abc9c;">Ships within 1-3 business days after receipt of your payment</p>
523 RoofLITE+ SOLID PINE | wooden, pivot, 2-glass roof window <p> Ships within 6-10 business days after receipt of your payment</p>
517 RoofLITE+ SLIM VENT | wooden, pivot, 2-glass roof window with with ventilation valve
8871 VELUX GGL 3070Q | wooden, pivot roof window with safe 2-glazing
10210 VELUX GPL 3068 | wooden, top hung roof window with safe 3-glazing
9822 VELUX GLU 0064 | PVC roof window, centre pivot, 3-glass