SELECT 
  product_id 
FROM 
  cscart_product_popularity 
WHERE 
  product_id IN (342, 343, 344, 345)

Query time 0.00026

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_popularity range PRIMARY,total PRIMARY 3 4 Using where; Using index

Result

product_id
342
343
344
345