SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'af09d453b7356178a579f96032a4e044d5bf6d7c8cc7ffec9a8bef48b94e61f2' 
  AND token = 'hnqONCJMvfl5QAblrZz8Wq/MwwTHYIm3hZx2RivUtXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}