SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff352ab0898192e58f9cf648f78a052bb1596c605eb6495ccc0d8975d2650868' 
  AND token = 'tKWuCaPWySEzFZXthLubQrwDGDmhNPcM/5DUZ+d8GMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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