SELECT 
  cscart_product_prices.product_id, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_product_prices 
WHERE 
  cscart_product_prices.product_id IN (
    238, 239, 245, 242, 243, 65, 64, 63, 66, 
    62, 134, 135, 33, 32, 246, 71, 70, 69, 
    68, 67, 155, 153, 154, 190, 189, 168, 
    167, 169, 165, 166, 86, 106, 105, 101, 
    146, 147, 145, 156, 157, 148, 149, 30, 
    29, 248, 140, 141, 144, 143, 142, 37, 
    53, 52, 24, 18, 16, 23, 4, 5, 22, 1, 113, 
    117, 125, 120, 133, 132, 175, 173, 172, 
    25, 161, 163, 184, 180, 183, 164, 59, 
    58, 56, 57, 55, 60, 42, 39, 40, 43, 50, 
    51, 49, 48, 54, 74, 73, 75, 72, 76
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id

Query time 0.00104

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "cscart_product_prices.product_id",
      "temporary_table": {
        "table": {
          "table_name": "cscart_product_prices",
          "access_type": "ALL",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "rows": 253,
          "filtered": 61.03489685,
          "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (238,239,245,242,243,65,64,63,66,62,134,135,33,32,246,71,70,69,68,67,155,153,154,190,189,168,167,169,165,166,86,106,105,101,146,147,145,156,157,148,149,30,29,248,140,141,144,143,142,37,53,52,24,18,16,23,4,5,22,1,113,117,125,120,133,132,175,173,172,25,161,163,184,180,183,164,59,58,56,57,55,60,42,39,40,43,50,51,49,48,54,74,73,75,72,76) and cscart_product_prices.usergroup_id in (0,1)"
        }
      }
    }
  }
}

Result

product_id price
1 648000.000000
4 84000.000000
5 108000.000000
16 42000.000000
18 36000.000000
22 96000.000000
23 72000.000000
24 54000.000000
25 72000.000000
29 24000.000000
30 42000.000000
32 36000.000000
33 20400.000000
37 19200.000000
39 50280.000000
40 27480.000000
42 9480.000000
43 44280.000000
48 21600.000000
49 14400.000000
50 26400.000000
51 21600.000000
52 16800.000000
53 4680.000000
54 32280.000000
55 43080.000000
56 26400.000000
57 37080.000000
58 93480.000000
59 71880.000000
60 179880.000000
62 25200.000000
63 22800.000000
64 22800.000000
65 12000.000000
66 46800.000000
67 40800.000000
68 96000.000000
69 63600.000000
70 60000.000000
71 63600.000000
72 72000.000000
73 70800.000000
74 63000.000000
75 58800.000000
76 52800.000000
86 43080.000000
101 22680.000000
105 20400.000000
106 21600.000000
113 54000.000000
117 87600.000000
120 24000.000000
125 18000.000000
132 32400.000000
133 27600.000000
134 10800.000000
135 0.000000
140 12000.000000
141 12000.000000
142 48000.000000
143 9600.000000
144 12000.000000
145 9600.000000
146 5400.000000
147 5400.000000
148 26280.000000
149 10800.000000
153 6000.000000
154 48000.000000
155 9600.000000
156 35880.000000
157 59880.000000
161 33600.000000
163 108000.000000
164 30000.000000
165 72000.000000
166 90000.000000
167 72000.000000
168 210000.000000
169 90000.000000
172 36000.000000
173 42000.000000
175 21600.000000
180 24000.000000
183 30000.000000
184 36000.000000
189 210000.000000
190 108000.000000
238 66240.000000
239 66240.000000
242 29880.000000
243 29880.000000
245 699.000000
246 48000.000000
248 44680.000000