SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ecb783972f8bef0d84ba1bc93ffd69400b75cb4a6304efe262c0170bd9e3105' 
  AND token = '1IYkUH9LzZpDjCx4zKKYpYRNKyBOsBMO2W5//4l6QSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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