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 = 7146 
WHERE 
  cscart_products_categories.product_id IN (
    96302, 96303, 96712, 96716, 96721, 96729, 
    96730, 96731, 96736, 96737, 96750, 
    96753, 96754, 96768, 96769, 96788, 
    97012, 97020, 97036, 97043, 97049, 
    97051, 97055, 97810, 97814, 97816, 
    97817, 97834, 97838, 97840, 97988, 
    97992, 98030, 98034, 98159, 98163, 
    98167, 98224, 98225, 98226, 98227, 
    98228, 98234, 98235, 98236, 98237, 
    98238, 98239, 98240, 98241, 98242, 
    98243, 98244, 98245, 98246, 98247, 
    98248, 98249, 98688, 98691, 98692, 
    98697, 98740, 98744, 98748, 99570, 
    99581, 99585, 100068, 100071, 100151, 
    100155, 100175, 100177, 100179, 100322, 
    100325, 100602, 100603, 100604, 100608, 
    100609, 100611, 100696, 100697, 100698, 
    100699, 100886, 100902, 100909, 100915, 
    100917, 100921, 101114, 101123, 101132
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00101

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "54.77"
    },
    "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": 96,
            "rows_produced_per_join": 96,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "9.89",
              "eval_cost": "9.60",
              "prefix_cost": "19.49",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (96302,96303,96712,96716,96721,96729,96730,96731,96736,96737,96750,96753,96754,96768,96769,96788,97012,97020,97036,97043,97049,97051,97055,97810,97814,97816,97817,97834,97838,97840,97988,97992,98030,98034,98159,98163,98167,98224,98225,98226,98227,98228,98234,98235,98236,98237,98238,98239,98240,98241,98242,98243,98244,98245,98246,98247,98248,98249,98688,98691,98692,98697,98740,98744,98748,99570,99581,99585,100068,100071,100151,100155,100175,100177,100179,100322,100325,100602,100603,100604,100608,100609,100611,100696,100697,100698,100699,100886,100902,100909,100915,100917,100921,101114,101123,101132))"
          }
        },
        {
          "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": "24.00",
              "eval_cost": "0.48",
              "prefix_cost": "53.09",
              "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')))"
          }
        },
        {
          "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": 4,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "1.20",
              "eval_cost": "0.48",
              "prefix_cost": "54.77",
              "data_read_per_join": "76"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}