SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d0d8d7993285c62defac7bd45d8faba39ee1d751f2d536f8bb75379950a665c' 
  AND token = 'Vyj+XypvQRswUtpFjwNv9ZENTiVFgdfuGmrhHPxRLZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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