SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9dd0363a405c8fb3aa170059ea9257f30cdf81193d6622ccbc6c5847031357a' 
  AND token = 'CWWRfO+ehBmV1FiqwUlVyWD3aG2r0IsAuS4Te4gVJlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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