SELECT 
  cscart_settings_objects.object_id as object_id, 
  name, 
  section_id, 
  section_tab_id, 
  type, 
  position, 
  is_global, 
  cscart_settings_objects.name as description, 
  (
    CASE WHEN storefront_values.object_id IS NOT NULL THEN storefront_values.value ELSE cscart_settings_objects.value END
  ) AS value 
FROM 
  cscart_settings_objects 
  LEFT JOIN cscart_settings_vendor_values AS storefront_values ON storefront_values.object_id = cscart_settings_objects.object_id 
  AND storefront_values.storefront_id = 1 
  AND storefront_values.company_id = 0 
WHERE 
  1 
  AND section_id = 99 
  AND (
    FIND_IN_SET(
      'STOREFRONT', cscart_settings_objects.edition_type
    ) 
    OR FIND_IN_SET(
      'ROOT', cscart_settings_objects.edition_type
    ) 
    OR FIND_IN_SET(
      'MVE:STOREFRONT', cscart_settings_objects.edition_type
    ) 
    OR FIND_IN_SET(
      'MVE:ROOT', cscart_settings_objects.edition_type
    )
  ) 
  AND cscart_settings_objects.type <> 'H' 
ORDER BY 
  cscart_settings_objects.position

Query time 0.00025

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE storefront_values system PRIMARY,storefront_id,company_id 0 const row not found
1 SIMPLE cscart_settings_objects ref section_id section_id 4 const 24 Using where; Using filesort

Result

object_id name section_id section_tab_id type position is_global description value
5919 clear_url 99 100 O 10 N clear_url
5921 site_change 99 100 S 30 N site_change daily
5922 site_priority 99 100 S 40 N site_priority 1
5924 include_products 99 100 C 60 N include_products Y
5925 products_change 99 100 S 70 N products_change daily
5926 products_priority 99 100 S 80 N products_priority 0.5
5928 include_categories 99 100 C 100 N include_categories Y
5929 categories_change 99 100 S 110 N categories_change daily
5930 categories_priority 99 100 S 120 N categories_priority 0.5
5932 include_pages 99 100 C 140 N include_pages Y
5933 pages_change 99 100 S 150 N pages_change daily
5934 pages_priority 99 100 S 160 N pages_priority 0.5
5936 include_extended 99 100 C 180 N include_extended Y
5937 extended_change 99 100 S 190 N extended_change daily
5938 extended_priority 99 100 S 200 N extended_priority 0.5
5940 include_companies 99 100 C 220 N include_companies Y
5941 companies_change 99 100 S 230 N companies_change daily
5942 companies_priority 99 100 S 240 N companies_priority 0.5