SELECT 
  feature_id 
FROM 
  cscart_product_features 
  INNER JOIN cscart_ult_objects_sharing ON (
    cscart_ult_objects_sharing.share_object_id = cscart_product_features.feature_id 
    AND cscart_ult_objects_sharing.share_company_id = 3 
    AND cscart_ult_objects_sharing.share_object_type = 'product_features'
  ) 
WHERE 
  feature_id IN (30) 
  AND feature_type = 'E'

Query time 0.00051

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_features const PRIMARY PRIMARY 3 const 1
1 SIMPLE cscart_ult_objects_sharing const PRIMARY PRIMARY 159 const,const,const 1 Using index

Result

feature_id
30