SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb4e6d6c0f76aa19288972b9dff550d663923cf9411c453a96d913c1aae44937' 
  AND token = 'vDUsqlzlJZQ/chPHTh2pphZslhueMBBH0KcN4zooTno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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