SELECT 
  et_menu_id, 
  categ_id, 
  size, 
  thumbnails, 
  icon, 
  text, 
  banner, 
  products 
FROM 
  cscart_et_category_menu 
WHERE 
  1 
  AND cscart_et_category_menu.lang_code = 'en' 
  AND cscart_et_category_menu.categ_id IN (
    266, 395, 394, 9940, 9941, 9942, 9943
  )

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.81"
    },
    "table": {
      "table_name": "cscart_et_category_menu",
      "access_type": "range",
      "possible_keys": [
        "categ_id"
      ],
      "key": "categ_id",
      "used_key_parts": [
        "categ_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 7,
      "rows_produced_per_join": 7,
      "filtered": "100.00",
      "index_condition": "((`webmarco`.`cscart_et_category_menu`.`lang_code` = 'en') and (`webmarco`.`cscart_et_category_menu`.`categ_id` in (266,395,394,9940,9941,9942,9943)))",
      "cost_info": {
        "read_cost": "15.41",
        "eval_cost": "1.40",
        "prefix_cost": "16.81",
        "data_read_per_join": "560"
      },
      "used_columns": [
        "et_menu_id",
        "categ_id",
        "size",
        "thumbnails",
        "icon",
        "text",
        "banner",
        "lang_code",
        "products"
      ]
    }
  }
}