SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a401179762d11cce2a575e4dbd2e4b7d36b6991e1426941a1ae1e167c5e8e9a1' 
  AND token = 'udNcRmGCw32+4ph0aQqWojyqPnWffjxhjSgiLjVfOGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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