SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 166 
WHERE 
  cscart_products_categories.product_id IN (
    70, 156, 175, 43, 76, 56, 57, 30, 246, 173, 
    67, 25
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00116

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13342.44"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "12066.43"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "rows_examined_per_scan": 84,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "8.91",
              "eval_cost": "0.34",
              "prefix_cost": "9.25",
              "data_read_per_join": "8K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`mobikul_delivery_boy_livedemo`.`cscart_categories`.`storefront_id` in (0,1)) and ((`mobikul_delivery_boy_livedemo`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`mobikul_delivery_boy_livedemo`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`mobikul_delivery_boy_livedemo`.`cscart_categories`.`usergroup_ids`))) and (`mobikul_delivery_boy_livedemo`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ALL",
            "rows_examined_per_scan": 268,
            "rows_produced_per_join": 45,
            "filtered": "5.00",
            "using_join_buffer": "hash join",
            "cost_info": {
              "read_cost": "14.27",
              "eval_cost": "4.50",
              "prefix_cost": "68.54",
              "data_read_per_join": "720"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "((`mobikul_delivery_boy_livedemo`.`cscart_products_categories`.`category_id` = `mobikul_delivery_boy_livedemo`.`cscart_categories`.`category_id`) and (`mobikul_delivery_boy_livedemo`.`cscart_products_categories`.`product_id` in (70,156,175,43,76,56,57,30,246,173,67,25)))"
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "ALL",
            "rows_examined_per_scan": 268,
            "rows_produced_per_join": 12066,
            "filtered": "100.00",
            "using_join_buffer": "hash join",
            "cost_info": {
              "read_cost": "0.83",
              "eval_cost": "1206.64",
              "prefix_cost": "1276.01",
              "data_read_per_join": "188K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ],
            "attached_condition": "<if>(is_not_null_compl(product_position_source), ((`mobikul_delivery_boy_livedemo`.`product_position_source`.`category_id` = 166) and (`mobikul_delivery_boy_livedemo`.`product_position_source`.`product_id` = `mobikul_delivery_boy_livedemo`.`cscart_products_categories`.`product_id`)), true)"
          }
        }
      ]
    }
  }
}