SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5874231a52044c4fd9b1e5964c1c110140ab49f7374ffdaec1d3121e2cdba18c' 
  AND token = 'kOGaDZPmPJDMlqQnZk1OU5/9ZIAxMVKsgQh2mXRY62g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}