SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b8d3b740cb9a2e2fbe8d21c9fafe8c6ea3e54c63229fa95c5aca0caf7d17f99' 
  AND token = 'nDivNFDfLSM+g2zCDZZgYTe2UCnjQpnS41zGvH9S+tA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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