SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cdcdd0ae5bed319fb1802229510f6b778a66f3fe75ac32aa8441667f46e9963' 
  AND token = 'BUiez8T3dwZ+TmAfDmmj507jkhBbgbnAChSNwjlWHmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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