SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0d0701841416017b4f342adf8a6265f093b0b464616e395262e68ae99afa784d' 
  AND token = 'gp/xbUISIEkj3lb67fjfMlLaRORBnLWBpRadz99Kktg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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