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 = 7184 
WHERE 
  cscart_products_categories.product_id IN (
    96326, 96327, 96328, 96329, 96330, 96331, 
    96332, 96333, 96334, 96335, 96336, 
    96337, 96338, 96339, 96340, 96341, 
    96342, 96343, 96344, 96345, 96346, 
    96347, 96348, 96601, 96602, 96603, 
    96604, 96605, 96606, 96607, 96608, 
    96609, 96610, 96611, 96612, 96613, 
    96614, 96615, 96616, 96617, 96618, 
    96619, 96620, 96621, 96622, 96623, 
    96624, 96625, 96626, 96627, 96628, 
    96629, 96668, 96669, 96670, 96671, 
    96672, 96673, 96674, 96675, 96676, 
    96678, 96680, 96681, 96682, 96683, 
    96686, 96687, 96688, 96689, 96690, 
    96691, 96692, 96694, 97015, 97016, 
    97017, 97022, 97023, 97024, 97025, 
    97026, 97027, 97028, 97029, 97030, 
    97031, 97032, 97033, 97039, 97040, 
    97045, 97046, 97083, 97219, 97220
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00259

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "137.68"
    },
    "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": 242,
            "rows_produced_per_join": 242,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "24.55",
              "eval_cost": "24.20",
              "prefix_cost": "48.75",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (96326,96327,96328,96329,96330,96331,96332,96333,96334,96335,96336,96337,96338,96339,96340,96341,96342,96343,96344,96345,96346,96347,96348,96601,96602,96603,96604,96605,96606,96607,96608,96609,96610,96611,96612,96613,96614,96615,96616,96617,96618,96619,96620,96621,96622,96623,96624,96625,96626,96627,96628,96629,96668,96669,96670,96671,96672,96673,96674,96675,96676,96678,96680,96681,96682,96683,96686,96687,96688,96689,96690,96691,96692,96694,97015,97016,97017,97022,97023,97024,97025,97026,97027,97028,97029,97030,97031,97032,97033,97039,97040,97045,97046,97083,97219,97220))"
          }
        },
        {
          "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": 12,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "60.50",
              "eval_cost": "1.21",
              "prefix_cost": "133.45",
              "data_read_per_join": "31K"
            },
            "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": 12,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "3.03",
              "eval_cost": "1.21",
              "prefix_cost": "137.68",
              "data_read_per_join": "193"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        }
      ]
    }
  }
}