SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3533454c76b0b4f99578911726d649144ab19a1862f55022892f1b0268612632' 
  AND token = 'KI2DpLEf34S3fisEyRHGzNW/qSdQTIUMWDZAU5qxRzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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