SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04845730a0e1ab44d55f1495037f971df88b9e82705cc0667093255c766c324f' 
  AND token = 'dF951ON4PpugvxHF7bq2YY/9qJtbN+IQQv4ZOHbjCF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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