SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f991e92e3587f6422502008e5ccda368ab82864e1ae6acd60977a30578d73f8' 
  AND token = 'POJPwYDPi9HC432XSSL7DP3KFPKkGN8qY4FavN8cJKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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