SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3c48b49d3f18b7e606e95f3203771f4773d9db5c7e96160c5ac51541efd4ce' 
  AND token = '7ACbV2M+/hkC/lmuvkUfo8PPXRgqySWg2javZ6LvK/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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