SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135fb31766d1f72f0a8f325eae58fa05473d130b33765319f866f122a77bce8d' 
  AND token = 'cmDX8IW//fiLu0RuuhQRiruHkAxvgBPaWZqah9wAXQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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