SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f1c306eade1dc7ff10301f7df1acb584b9622429239cd73e448bd4395716c7' 
  AND token = 'xR2O2IQzxfc7qSx1E6WpNDTymtDBhVG4ZYaLfsPwBIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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