SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4a743533e3a6f85d9f07646dd47e4d7aadd2c4c836af33c92e073f1826212ba' 
  AND token = '+9uCCoN7I7tcGwU9vvgNsX7gCZKIBA4jCjGWDqfhIYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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