SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bf755db47c8384fddb736315f264b30fff35227cae198ee11b48c55decce391' 
  AND token = 'nkIAy5rC5n+p4rcK4klKoEcVu2f2XLe7wSUGETBv1+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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