SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5760f51efccb9c9c4d1ec1468a80f4558408bb39ad42e172f188112bafb0d36d' 
  AND token = 'fXwwsbgT6lkBaDNmLOzzi8p1dheFLwoSbOHRCMk4phc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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