SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9829be70c2635b7dea3782c20dbc43cd2e7ca6eedcdf91a8542b9780ec784722' 
  AND token = 'YxysVlFznDlSvOC13hnRIADcBmQBEe5WCYlIpBgNJiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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