SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af3d8ddaad46f73dc81f8e3da4ecdc4ec467ac3544a112ca0025d81de457d50a' 
  AND token = 'jPCiQRqkiAhYdYxxjKzSm5VJlkHGCI7QhWUO5a/R8GI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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