SELECT 
  product_id, 
  is_stock_split_by_warehouses 
FROM 
  cscart_products 
WHERE 
  product_id IN (834)

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}