SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cd7dff4f89d659135079f6eac76277ad25ac15b3de0263b30c3ba6c00b6e46f' 
  AND token = 'Z6BWCbGgI0YZcmU+8Q9mhzjm+g5x8jMVQtbc4ZhGj0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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