SELECT 
  q_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      q_products_categories.link_type = "M", 
      CONCAT(
        q_products_categories.category_id, 
        "M"
      ), 
      q_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  q_products_categories 
  INNER JOIN q_categories ON q_categories.category_id = q_products_categories.category_id 
  AND (
    q_categories.usergroup_ids = '' 
    OR FIND_IN_SET(0, q_categories.usergroup_ids) 
    OR FIND_IN_SET(1, q_categories.usergroup_ids)
  ) 
  AND q_categories.status IN ('A', 'H') 
WHERE 
  q_products_categories.product_id IN (
    8653, 8654, 8655, 8656, 8657, 8658, 8659, 
    8660, 8661, 8203, 8204, 8205, 8207, 
    8208, 8209, 8210
  ) 
GROUP BY 
  q_products_categories.product_id

Query time 0.00065

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "57.61"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "q_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 16,
            "rows_produced_per_join": 16,
            "filtered": "100.00",
            "index_condition": "(`portal`.`q_products_categories`.`product_id` in (8653,8654,8655,8656,8657,8658,8659,8660,8661,8203,8204,8205,8207,8208,8209,8210))",
            "cost_info": {
              "read_cost": "35.21",
              "eval_cost": "3.20",
              "prefix_cost": "38.41",
              "data_read_per_join": "256"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "q_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "portal.q_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 3,
            "filtered": "20.00",
            "cost_info": {
              "read_cost": "16.00",
              "eval_cost": "0.64",
              "prefix_cost": "57.61",
              "data_read_per_join": "8K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "(((`portal`.`q_categories`.`usergroup_ids` = '') or find_in_set(0,`portal`.`q_categories`.`usergroup_ids`) or find_in_set(1,`portal`.`q_categories`.`usergroup_ids`)) and (`portal`.`q_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
8203 166M
8204 166M
8205 166M
8207 274M
8208 546M
8209 546M
8210 546M
8653 41M
8654 40M
8655 41M
8656 40M
8657 40M
8658 38M
8659 41M
8660 41M
8661 40M