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 (
    206, 207, 208, 209, 210, 211, 212, 213, 
    215, 217, 218, 220, 222, 224, 225, 226, 
    227, 228, 229, 230, 231, 232, 233, 234, 
    235, 236, 237, 238, 239, 242, 243, 78, 
    79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 
    89, 90, 91, 92, 93, 94
  ) 
  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 0.00090

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "173.31"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "96.00"
      },
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "ALL",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "rows_examined_per_scan": 368,
        "rows_produced_per_join": 95,
        "filtered": "26.09",
        "cost_info": {
          "read_cost": "58.11",
          "eval_cost": "19.20",
          "prefix_cost": "77.31",
          "data_read_per_join": "2K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`danishecarter_latest`.`cscart_product_prices`.`lower_limit` = 1) and (`danishecarter_latest`.`cscart_product_prices`.`product_id` in (206,207,208,209,210,211,212,213,215,217,218,220,222,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,242,243,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94)) and (`danishecarter_latest`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
78 100.00000000
79 96.00000000
80 55.00000000
81 49.50000000
82 19.99000000
83 19.99000000
84 19.99000000
85 19.99000000
86 359.00000000
87 19.99000000
88 39.99000000
89 19.99000000
90 19.99000000
91 10700.00000000
92 3225.00000000
93 19.99000000
94 59.99000000
206 179.99000000
207 42.00000000
208 82.94000000
209 109.99000000
210 89.99000000
211 299.99000000
212 129.95000000
213 295.00000000
215 1095.00000000
217 610.99000000
218 459.99000000
220 1099.99000000
222 529.99000000
224 479.99000000
225 199.99000000
226 269.99000000
227 699.00000000
228 349.99000000
229 299.99000000
230 125.00000000
231 99.00000000
232 79.95000000
233 47.99000000
234 59.99000000
235 79.99000000
236 299.99000000
237 299.99000000
238 499.99000000
239 509.99000000
242 249.00000000
243 249.00000000