SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b470389ddd23cf139b710b75dbe872309447046070e1c0d5315d5c22e7b499' 
  AND token = 'dJ1k7xYOTEeO+KRiJmES800g14PWLhUBHj+5aLzT/ZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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