SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '25355cb7017f9c4742c37961fde8fbbb953b8c04ddb7ff20bc40297a68cf5874' 
  AND token = 'v9HLeBAVmaGPTFDITxiEHhNGgR8/rGk2WkcvD3tYDgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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