SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47972f1b32ac9ed0c72a206a15c40959d1751938b33675429b8c467b211918b8' 
  AND token = 'v8dlpkg86+iulnock9K9UEMUDlSX0K87mXAjbpiQcC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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