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, 
  product_position_source.position AS position 
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') 
  LEFT JOIN q_products_categories AS product_position_source ON q_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 192 
WHERE 
  q_products_categories.product_id IN (
    8790, 8791, 8792, 9050, 9052, 9053, 9054, 
    9055, 9056, 9057, 9058, 9817, 9818, 
    9819, 9820, 9821, 9822, 9823, 9824, 
    9825, 9826, 9827, 9828, 9829, 9830, 
    9831, 9832, 9833, 9834, 9835
  ) 
GROUP BY 
  q_products_categories.product_id

Query time 0.00086

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "151.61"
    },
    "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": 32,
            "rows_produced_per_join": 32,
            "filtered": "100.00",
            "index_condition": "(`portal`.`q_products_categories`.`product_id` in (8790,8791,8792,9050,9052,9053,9054,9055,9056,9057,9058,9817,9818,9819,9820,9821,9822,9823,9824,9825,9826,9827,9828,9829,9830,9831,9832,9833,9834,9835))",
            "cost_info": {
              "read_cost": "68.41",
              "eval_cost": "6.40",
              "prefix_cost": "74.81",
              "data_read_per_join": "512"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "portal.q_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 32,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "32.00",
              "eval_cost": "6.40",
              "prefix_cost": "113.21",
              "data_read_per_join": "512"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "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": 6,
            "filtered": "20.00",
            "cost_info": {
              "read_cost": "32.00",
              "eval_cost": "1.28",
              "prefix_cost": "151.61",
              "data_read_per_join": "16K"
            },
            "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 position
8790 192M 0
8791 192M 0
8792 192M 0
9050 192M 0
9052 192M 0
9053 192M 0
9054 192M 0
9055 192M 0
9056 192M 0
9057 192M 0
9058 192M 0
9817 192M 0
9818 192M 0
9819 192M 0
9820 192M 0
9821 192M 0
9822 192M 0
9823 192M 0
9824 192M 0
9825 192M 0
9826 192M 0
9827 192M 0
9828 192M 0
9829 192M 0
9830 192M 0
9831 192M 0
9832 192M 0
9833 192M 0
9834 192M 0
9835 192M 0