SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a4a227483c6ae0a3f19f09a787b4e0ab99cc804ac38d329609a285c60331dba' 
  AND token = 'DUAjXdRG8Urpe/yzYWXvnphRdvTcMm5DTXfcwso64WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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