SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02413d5496579cd8ddec5eebeb0e3e63b9e784e8180887870e225e0b79f4f131' 
  AND token = 'iHu3kpOvhdPLhIhZLNgs+IQ3JLlOdswlwIZxcpK86vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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