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 = 7257 
WHERE 
  cscart_products_categories.product_id IN (
    95825, 95826, 95827, 95828, 95830, 95831, 
    95867, 95868, 95869, 95870, 95871, 
    95872, 95873, 95874, 95875, 95876, 
    95877, 95878, 95879, 95880, 95881, 
    95882, 95883, 95884, 95889, 95891, 
    95892, 95895, 95896, 95897
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01643

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "87.59"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 97,
            "rows_produced_per_join": 97,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "10.00",
              "eval_cost": "9.70",
              "prefix_cost": "19.70",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (95825,95826,95827,95828,95830,95831,95867,95868,95869,95870,95871,95872,95873,95874,95875,95876,95877,95878,95879,95880,95881,95882,95883,95884,95889,95891,95892,95895,95896,95897))"
          }
        },
        {
          "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",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 97,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "24.25",
              "eval_cost": "9.70",
              "prefix_cost": "53.65",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 4,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "24.25",
              "eval_cost": "0.49",
              "prefix_cost": "87.60",
              "data_read_per_join": "12K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
95825 7320,7260M
95826 7320,7260M
95827 7349,7261M
95828 7349,7261M
95830 7208M,7346,7309,7241
95831 7309,7208M,7346,7241
95867 7258M
95868 7258M
95869 7241,7208M,7309,7346
95870 7208M,7241,7309,7346
95871 7208M,7346,7241,7309
95872 7208M,7309,7241,7346
95873 7208M,7309,7241,7346
95874 7309,7241,7346,7208M
95875 7309,7241,7208M,7346
95876 7309,7346,7208M,7241
95877 7208M,7241,7346,7309
95878 7208M,7241,7309,7346
95879 7346,7309,7208M,7241
95880 7241,7346,7309,7208M
95881 7241,7309,7346,7208M
95882 7241,7346,7208M,7309
95883 7346,7208M,7241,7309
95884 7346,7309,7241,7208M
95889 7258M
95891 7258M
95892 7258M
95895 7208M,7241,7309,7346
95896 7208M,7241,7346,7309
95897 7241,7208M,7346,7309