SELECT 
  * 
FROM 
  cscart_user_profiles 
WHERE 
  user_id = 6 
  AND profile_type = 'P'

Query time 0.00007

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_user_profiles",
          "access_type": "ref",
          "possible_keys": ["uid_p", "profile_type"],
          "key": "uid_p",
          "key_length": "6",
          "used_key_parts": ["user_id", "profile_type"],
          "ref": ["const", "const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "cscart_user_profiles.profile_type = 'P'"
        }
      }
    ]
  }
}