SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c708fa9bb311f92acd4e7714180b559966cb9d6f552306605ba0ac16bd63f4' 
  AND token = 'XvUomaKOt+ICjNHcHZuHK+uKvkeeYwN0AYfyeTD6fwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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