SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0679fcc9e050b8a4bedfffd543e29b99c3f5442afaaa3d5f9db25ae12aa54c12' 
  AND token = 'yv9UtXJ6EROPjCycbaqBnBMawdXZgZXBwg0dNIbRLzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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