SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9b9300ca6606730dcaeb47d5509354a61ff8bdfd4e9731703360a477431f673' 
  AND token = 'jDsjc3esJMCFh/Ju0LGBQSv8Kj8mmsTT4g1deUz/j70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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