SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd73610ee0fb3fcc00bf24e198edf4bd6e0e182b11943c81b1059e21eb825aae1' 
  AND token = 'KDYC+omUka7T9l2zXIgJMK/MVtkD/baEQrQWHEp+LoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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