SELECT 
  warehouse_id, 
  amount, 
  store_type, 
  position, 
  main_destination_id, 
  pickup_destinations_ids, 
  shipping_destinations_ids, 
  status 
FROM 
  cscart_store_locations AS sl 
  INNER JOIN cscart_warehouses_products_amount AS wpa ON wpa.warehouse_id = sl.store_location_id 
WHERE 
  wpa.product_id = 217068 
ORDER BY 
  sl.position ASC

Query time 0.00073

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "sl.position",
      "temporary_table": {
        "table": {
          "table_name": "wpa",
          "access_type": "ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "sl",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["store_location_id"],
          "ref": ["staging2_wesave_com.wpa.warehouse_id"],
          "rows": 1,
          "filtered": 100
        }
      }
    }
  }
}