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SELECT 
  cscart_ult_product_prices.product_id, 
  MIN(
    IF(
      cscart_ult_product_prices.percentage_discount = 0, 
      cscart_ult_product_prices.price, 
      cscart_ult_product_prices.price - (
        cscart_ult_product_prices.price * cscart_ult_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_ult_product_prices 
WHERE 
  cscart_ult_product_prices.product_id IN (
    278, 
    280, 
    282, 
    247, 
    248, 
    241, 
    244, 
    245, 
    246, 
    240, 
    6, 
    66, 
    166, 
    214, 
    219, 
    221, 
    223, 
    192, 
    194, 
    195, 
    196, 
    197, 
    198, 
    199, 
    200, 
    201, 
    202, 
    203, 
    204, 
    205, 
    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, 
    95, 
    96, 
    97, 
    100, 
    101, 
    102, 
    103, 
    104, 
    105, 
    106, 
    107, 
    108, 
    109, 
    110, 
    111, 
    112, 
    113, 
    114, 
    115, 
    116, 
    117, 
    118, 
    119, 
    120, 
    121, 
    122, 
    123, 
    124, 
    125, 
    126, 
    127, 
    128, 
    129, 
    130, 
    131, 
    132, 
    133, 
    134, 
    135, 
    136, 
    137, 
    138, 
    139, 
    140, 
    141, 
    142, 
    143, 
    144, 
    145, 
    146
  ) 
  AND cscart_ult_product_prices.lower_limit = 1 
  AND cscart_ult_product_prices.company_id = 1 
  AND cscart_ult_product_prices.usergroup_id IN (0, 0, 1) 
GROUP BY 
  cscart_ult_product_prices.product_id

Query time 0.00116

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "cscart_ult_product_prices.product_id",
      "temporary_table": {
        "table": {
          "table_name": "cscart_ult_product_prices",
          "access_type": "ALL",
          "possible_keys": [
            "usergroup",
            "product_id",
            "company_id",
            "lower_limit",
            "usergroup_id"
          ],
          "rows": 4,
          "filtered": 100,
          "attached_condition": "cscart_ult_product_prices.lower_limit = 1 and cscart_ult_product_prices.company_id = 1 and cscart_ult_product_prices.product_id in (278,280,282,247,248,241,244,245,246,240,6,66,166,214,219,221,223,192,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,215,217,218,220,222,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,242,243,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146) and cscart_ult_product_prices.usergroup_id in (0,0,1)"
        }
      }
    }
  }
}