SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e927beeda10d2d1698b345278ffc177d3b95524119718c9a5c1b2bd90200914' 
  AND token = 'rKWMV9IVvlsD6C7xghCpLQhQl96eP1ZJbSl4rA7Ve4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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