SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06cee2ff4f0f310aabde025a7f4cf90b7f3b985d256ecd869b6075348fdc7517' 
  AND token = 'grzZKKyxOuvqKMvdEFAd4X+6akz8JLspIKdm88OlnlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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