SELECT 
  * 
FROM 
  cscart_product_feature_variants 
WHERE 
  variant_id IN (
    2998, 4796, 4792, 4766, 4763, 4779, 4784, 
    5163, 5164, 5179, 5180, 4754, 1882, 
    3096, 3095, 3097, 3098, 4981, 3099, 
    3100, 3101, 3102, 3104, 5176, 5029, 
    4974, 4983, 3085, 5063, 4915, 3087, 
    3686, 3088, 3089, 3090, 3091, 3092, 
    3093, 3094, 3084, 5182, 1273, 1404, 
    4904, 4894, 1856, 1870, 4905, 0
  )

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_feature_variants",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["variant_id"],
          "rows": 49,
          "filtered": 100,
          "index_condition": "cscart_product_feature_variants.variant_id in (2998,4796,4792,4766,4763,4779,4784,5163,5164,5179,5180,4754,1882,3096,3095,3097,3098,4981,3099,3100,3101,3102,3104,5176,5029,4974,4983,3085,5063,4915,3087,3686,3088,3089,3090,3091,3092,3093,3094,3084,5182,1273,1404,4904,4894,1856,1870,4905,0)"
        }
      }
    ]
  }
}