SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd34e32d5b21e24a7a625fa98de7f603f9bb5a519ed34a4335ccaf583c1c7747' 
  AND token = 'iJaaAQr069QBz6MpTpcxPBZgheS6JN+DQ/eZICTeBfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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