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 (
    155, 156, 157, 158, 159, 160, 161, 162, 
    163, 164, 165, 166, 167, 168, 169, 170, 
    171, 172, 173, 174, 175, 176, 177, 178, 
    179, 180, 181, 182, 183, 184, 185, 186, 
    187, 188, 189, 190, 191, 192, 193, 194, 
    195, 196, 197, 198, 199, 200, 201, 202, 
    203, 204, 205, 206, 207, 208, 209, 210, 
    211, 212, 213, 214, 215, 216, 217, 218, 
    219, 220, 221, 222, 223, 224, 225, 226, 
    227, 228, 229, 230, 231, 232, 233, 234, 
    235, 236, 237, 238, 239, 240, 241, 242, 
    243, 244, 245, 246, 247, 248, 249, 250
  ) 
  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 0.00303

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_prices",
      "access_type": "range",
      "possible_keys": ["usergroup", "product_id", "lower_limit", "usergroup_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 96,
      "filtered": 19.59183121,
      "index_condition": "cscart_product_prices.product_id in (155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250)",
      "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
155 0.00000000
156 0.00000000
157 46000.00000000
158 0.00000000
159 0.00000000
160 18000.00000000
161 18000.00000000
162 18000.00000000
163 18000.00000000
164 18000.00000000
165 0.00000000
166 18000.00000000
167 0.00000000
168 18000.00000000
169 0.00000000
170 0.00000000
171 0.00000000
172 0.00000000
173 0.00000000
174 0.00000000
175 0.00000000
176 0.00000000
177 0.00000000
178 0.00000000
179 0.00000000
180 0.00000000
181 0.00000000
182 18000.00000000
183 0.00000000
184 0.00000000
185 0.00000000
186 0.00000000
187 18000.00000000
188 0.00000000
189 0.00000000
190 0.00000000
191 0.00000000
192 0.00000000
193 0.00000000
194 0.00000000
195 0.00000000
196 0.00000000
197 42000.00000000
198 0.00000000
199 0.00000000
200 0.00000000
201 0.00000000
202 0.00000000
203 0.00000000
204 0.00000000
205 0.00000000
206 125000.00000000
207 0.00000000
208 0.00000000
209 0.00000000
210 0.00000000
211 151200.00000000
212 80000.00000000
213 96000.00000000
214 78544.00000000
215 80000.00000000
216 80000.00000000
217 78544.00000000
218 0.00000000
219 0.00000000
220 0.00000000
221 0.00000000
222 0.00000000
223 0.00000000
224 22000.00000000
225 50000.00000000
226 50000.00000000
227 0.00000000
228 130000.00000000
229 130000.00000000
230 27000.00000000
231 43200.00000000
232 43200.00000000
233 43200.00000000
234 78544.00000000
235 78544.00000000
236 35000.00000000
237 35000.00000000
238 34000.00000000
239 49200.00000000
240 68400.00000000
241 0.00000000
242 58800.00000000
243 62400.00000000
244 62400.00000000
245 62400.00000000
246 62400.00000000
247 42000.00000000
248 0.00000000
249 32400.00000000
250 199200.00000000