SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e549c9365f572ebd8d525c7bd1541638700eca3c9858e28ea73da76ce214bb6e' 
  AND token = 'p3W0zOqKin/7K/t2RmJr3J+0u9w72k02SJTvU2L1Idw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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