SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ea5bd1f254f7ac1c1aeb746bea3357c477b8fd46545fe14afd6ccd98d2af8f2' 
  AND token = 'ShjoWMb9/+fnFCX3XP1jlxOyzT5hYg7XVg45TVgyBwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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