SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c62328c9a091a5cb1cab27e371af953b94e3f4dcea015469719822f563a6e3d' 
  AND token = 'x6p8ZpRTXkGKXBfeKpIccmfheDKUuE/7WzJEFxw4jG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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