SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ae87859df455d3255a8a60f0368b1a3dba6ce1f06e369d27fdca64bf921f38' 
  AND token = 'BkE6yU72AmF6KDE0OlL6PbYOCyuneVMm8YjS89LHqNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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