SELECT 
  object_id 
FROM 
  cscart_settings_objects 
  LEFT JOIN cscart_settings_sections ON cscart_settings_objects.section_id = cscart_settings_sections.section_id 
WHERE 
  cscart_settings_objects.name = 'wk_sticky_header_default_message'

Query time 0.00150

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "729.37"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_settings_objects",
          "access_type": "ALL",
          "rows_examined_per_scan": 534,
          "rows_produced_per_join": 53,
          "filtered": "10.00",
          "cost_info": {
            "read_cost": "50.44",
            "eval_cost": "5.34",
            "prefix_cost": "55.78",
            "data_read_per_join": "42K"
          },
          "used_columns": [
            "object_id",
            "name",
            "section_id"
          ],
          "attached_condition": "(`mobikul_delivery_boy_livedemo`.`cscart_settings_objects`.`name` = 'wk_sticky_header_default_message')"
        }
      },
      {
        "table": {
          "table_name": "cscart_settings_sections",
          "access_type": "ALL",
          "rows_examined_per_scan": 126,
          "rows_produced_per_join": 6728,
          "filtered": "100.00",
          "using_join_buffer": "hash join",
          "cost_info": {
            "read_cost": "0.75",
            "eval_cost": "672.84",
            "prefix_cost": "729.37",
            "data_read_per_join": "2M"
          },
          "used_columns": [
            "section_id"
          ],
          "attached_condition": "<if>(is_not_null_compl(cscart_settings_sections), (`mobikul_delivery_boy_livedemo`.`cscart_settings_sections`.`section_id` = `mobikul_delivery_boy_livedemo`.`cscart_settings_objects`.`section_id`), true)"
        }
      }
    ]
  }
}