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 = 7194 
WHERE 
  cscart_products_categories.product_id IN (
    87656, 87670, 87677, 87684, 87705, 87716, 
    87717, 87730, 87731, 90022, 90024, 
    90038, 90040, 90041, 87654, 87655, 
    87668, 87669, 87675, 87676, 87682, 
    87683, 87703, 87704, 87713, 87715, 
    87727, 87729, 88692, 88693, 88739, 
    88740, 90023, 90039, 90055, 87581, 
    87596, 87611, 88150, 88152, 88792, 
    87657, 87671, 87678, 87685, 87706, 
    87719, 87733, 88696, 88743, 88146, 
    88589, 84244, 84243, 88585, 84242, 
    88584, 88907, 88908, 88905, 88906, 
    88910, 88909, 92913, 92914, 92915, 
    92916, 92917, 92918, 92919, 92920, 
    92921, 93753, 93754, 93755, 93756, 
    93757, 93758, 93759, 93760, 93761, 
    93762, 93763, 93764, 93765, 93766, 
    93767, 93768, 93769, 93770, 93771, 
    93772, 93773, 93774, 93775, 93776
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00241

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 (87656,87670,87677,87684,87705,87716,87717,87730,87731,90022,90024,90038,90040,90041,87654,87655,87668,87669,87675,87676,87682,87683,87703,87704,87713,87715,87727,87729,88692,88693,88739,88740,90023,90039,90055,87581,87596,87611,88150,88152,88792,87657,87671,87678,87685,87706,87719,87733,88696,88743,88146,88589,84244,84243,88585,84242,88584,88907,88908,88905,88906,88910,88909,92913,92914,92915,92916,92917,92918,92919,92920,92921,93753,93754,93755,93756,93757,93758,93759,93760,93761,93762,93763,93764,93765,93766,93767,93768,93769,93770,93771,93772,93773,93774,93775,93776))"
          }
        },
        {
          "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"
            ]
          }
        }
      ]
    }
  }
}