SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83722bd7ef670cdbe5b1a5d7f2e8ebd68799d7ec8315acf1456fc5ddf2a81b67' 
  AND token = 'YRy9Mdi01iyXl69o3L41y8+UdvHSByIzP2vBkxlXTBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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