SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3e0868baa1cf20118af833b6fdb9e07fc5d85c1a04254a64c039b794f127d91' 
  AND token = 'y1XcykWp8OgYPhdxQKU717hMdrGnMyYbutBtkxIr3cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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