SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '502b03153e33fd3a86ca8cf4036e91761d64e97bd07cdcb6c6090002c078bd43' 
  AND token = 'jQrJEhZoePAWVNf7uYqsQ0+4lvNQne5l5u7wanJcVNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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