SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7529a5dfb5549819a43c909db8fddbf4691096f2d1069d79c86d8213abfc37c3' 
  AND token = 'lUxqlxz+/6tWAfu9kYGa91fMIq3QGiI+LvgQQxNxQJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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