SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1714fef9e57c4ab61ad480cfb9ba737557d8cb6ffac513d041a51f262a873300' 
  AND token = 'LJvIzIQThenF6fdVh7ItLY5PYafi8vnoPxinGiFbaVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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