SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '750761e97a19b5d9fffee159e5e7477ea50ce03102e3a35b9e3d5cf3cb2b8bdf' 
  AND token = 'slVxORQkR9Jgjui/UKpuHWtFqxhhQ5I9l78zdE+lBbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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