SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f241e178615550413c124d2aefdea4ba128f7bb23cae4f57304b7a2fbf49e1f' 
  AND token = 'lqDmIgcVdVS60d3xBqb/mk44XFWhpCQT/3zasqCuhvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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