SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86e1df548012f82dbc92f1bc721e967126830abeab258bc71013e9fea401b65b' 
  AND token = '8pv79KhLg1Fyb9TvHTCDnmkPJueUrE85ZQsjLy1TH7Q=' 
  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"
    }
  }
}