SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baad90ac7c5438fc16405c7044561e4196ba89cbaf8978c0d43828f7b7b4b539' 
  AND token = 'NXPJfJOp2XLwq+xqmihZOmNknL/Y8K/tYtfOgefwyY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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