SELECT 
  feature_id, 
  feature_type 
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 = 1 
    AND cscart_ult_objects_sharing.share_object_type = 'product_features'
  ) 
WHERE 
  feature_id IN (18, 549, 548)

Query time 0.00049

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_features range PRIMARY PRIMARY 3 3 Using index condition
1 SIMPLE cscart_ult_objects_sharing eq_ref PRIMARY PRIMARY 159 cscart_dev_4_16.cscart_product_features.feature_id,const,const 1 Using where; Using index

Result

feature_id feature_type
18 E
548 S
549 S