SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd30fd2c33d34912eca6c780c8b8495753c5865f94175f1da49cfe5d2be374667' 
  AND token = 'NQBoK3bDwkgOOzJgD9NiwtaSSNJLvWHf7RcIgg8It58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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