SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88cf673c14120d58a69033be7afebc74b71570b3bb5f44cf389f874a541e8956' 
  AND token = 'V7F8kWPa88352XFuD0sy0WH9uGQ/2FIkYBRHJaIKu/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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