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 = 21 
  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 0.00091

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "70.68"
    },
    "ordering_operation": {
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_settings_objects",
            "access_type": "ref",
            "possible_keys": [
              "section_id"
            ],
            "key": "section_id",
            "used_key_parts": [
              "section_id"
            ],
            "key_length": "4",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 31,
            "rows_produced_per_join": 27,
            "filtered": "90.00",
            "index_condition": "(`webmarco`.`cscart_settings_objects`.`section_id` <=> 21)",
            "cost_info": {
              "read_cost": "31.00",
              "eval_cost": "5.58",
              "prefix_cost": "37.20",
              "data_read_per_join": "22K"
            },
            "used_columns": [
              "object_id",
              "edition_type",
              "name",
              "section_id",
              "section_tab_id",
              "type",
              "value",
              "position",
              "is_global"
            ],
            "attached_condition": "((find_in_set('STOREFRONT',`webmarco`.`cscart_settings_objects`.`edition_type`) or find_in_set('ROOT',`webmarco`.`cscart_settings_objects`.`edition_type`) or find_in_set('MVE:STOREFRONT',`webmarco`.`cscart_settings_objects`.`edition_type`) or find_in_set('MVE:ROOT',`webmarco`.`cscart_settings_objects`.`edition_type`)) and (`webmarco`.`cscart_settings_objects`.`type` <> 'H'))"
          }
        },
        {
          "table": {
            "table_name": "storefront_values",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "storefront_id",
              "company_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "object_id",
              "company_id",
              "storefront_id"
            ],
            "key_length": "11",
            "ref": [
              "webmarco.cscart_settings_objects.object_id",
              "const",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 27,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "27.90",
              "eval_cost": "5.58",
              "prefix_cost": "70.68",
              "data_read_per_join": "669"
            },
            "used_columns": [
              "object_id",
              "company_id",
              "value",
              "storefront_id"
            ]
          }
        }
      ]
    }
  }
}