SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a38e5d01102a396f75718c651ebb4a38d28b97de8b6248fa3771f66c615529d' 
  AND token = 'Nd84mw4gnpz2FTFjK53tJOLJ0KkRvKiKtjOTyRy8TUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}