SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '831a892303d2dae0a0fa17fe33909854b476ce9988a7dc32ad73db3438fae3b2' 
  AND token = 'em6A7WMWKQeDWpjR4RYBYnNCBaAUEERdKBh1wyhX5qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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