SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac64858e25f61cd924525ef347557d274837863d59e6979196fce7179e8fe63e' 
  AND token = 'qsh3Sv9z25U5JnHsiPsL4mbmSMHkhmpikZurRG6zhFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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