SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d5dcf7237b665d74c51a698e4f6d236fb0b9c1e372ad6e16f7f782d68f8936d' 
  AND token = 'HX9ujYYfuEDpMBtOOBepZjcPVlb132OZbXLK2EjtimE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}