SELECT 
  cscart_product_point_prices.product_id, 
  MIN(
    cscart_product_point_prices.point_price
  ) AS point_price 
FROM 
  cscart_product_point_prices 
WHERE 
  cscart_product_point_prices.product_id IN (504, 1817) 
  AND cscart_product_point_prices.lower_limit = 1 
  AND cscart_product_point_prices.usergroup_id IN (0, 0, 1)

Query time 0.00045

JSON explain

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

Result

product_id point_price