SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec719fe777197af62294dd6c4e091412af4d722e5f6e17bad18c2dffe8bbd726' 
  AND token = 'AzIVPegLuVxVodcQparwFSjcNsIN8EPvX696ONtnZ0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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