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SELECT 
  product_id, 
  group_id 
FROM 
  cscart_product_variation_group_products 
WHERE 
  group_id IN (32, 57, 20, 44, 21, 37, 26, 34, 39, 47)

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_variation_group_products",
      "access_type": "index",
      "possible_keys": ["idx_group_id"],
      "key": "PRIMARY",
      "key_length": "6",
      "used_key_parts": ["product_id", "group_id"],
      "rows": 126,
      "filtered": 29.36507988,
      "attached_condition": "cscart_product_variation_group_products.group_id in (32,57,20,44,21,37,26,34,39,47)",
      "using_index": true
    }
  }
}

Result

product_id	group_id
111	32
125	34
129	39
131	47
140	26
142	44
146	21
149	20
150	57
177	37
181	20
182	20
183	21
184	21
193	26
194	26
211	32
212	32
213	32
214	32
215	32
216	32
217	32
218	32
224	34
225	34
233	37
234	37
237	39
238	39
258	44
259	44
273	47
274	47
293	57
294	57

product_id	group_id
111	32
125	34
129	39
131	47
140	26
142	44
146	21
149	20
150	57
177	37
181	20
182	20
183	21
184	21
193	26
194	26
211	32
212	32
213	32
214	32
215	32
216	32
217	32
218	32
224	34
225	34
233	37
234	37
237	39
238	39
258	44
259	44
273	47
274	47
293	57
294	57

product_id	group_id
111	32
125	34
129	39
131	47
140	26
142	44
146	21
149	20
150	57
177	37
181	20
182	20
183	21
184	21
193	26
194	26
211	32
212	32
213	32
214	32
215	32
216	32
217	32
218	32
224	34
225	34
233	37
234	37
237	39
238	39
258	44
259	44
273	47
274	47
293	57
294	57

product_id	group_id
111	32
125	34
129	39
131	47
140	26
142	44
146	21
149	20
150	57
177	37
181	20
182	20
183	21
184	21
193	26
194	26
211	32
212	32
213	32
214	32
215	32
216	32
217	32
218	32
224	34
225	34
233	37
234	37
237	39
238	39
258	44
259	44
273	47
274	47
293	57
294	57