SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c2bf91836efa9ef5ee66dd4f5f4df33b52ba285c7e9c31db54f674eed1e1967' 
  AND token = 'RwteRni2wcJzvyWLgq/d5FuU+TwqvaDcjdzLtjUt6fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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