SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4624940ce50e51ada0258cf24f8c2cfa903d5aee22bf3b73c9e24ba497969171' 
  AND token = 'HcBSseKdYjMUWOxGi3+fnnfXlLt9W2wer3KVffvqR6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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