SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bec5ebed2ac28f27532877b68a551ee1858e93f9c8faad8bb09a001bdc03d39' 
  AND token = 'Wy3BvHo5KA+xYUXU0O5w+JbejXpMvYzpwVVgTZw+f/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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