SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d78c10faec7c250eb093a18cceed455c694d0450263c40c9f67326c979b72c4' 
  AND token = 'OOb39KGsLL0w+2uLBX5L++wOqvQM8I4Dr0tArejq4sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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