SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1924d04e2e12cdedae55b5ae2c1354d5471c29743365dc0304d36e42ba7cef2d' 
  AND token = 'JyprMAY1k9rAfbGczWpBZOmFWGVOJ2ydkdwfUiOXHsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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