SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '467274568746e09d9405f093280e1a949fd9e60d5dd934c0af5ee7c283c5a274' 
  AND token = 'jWCNaXz7ErXCanFyGqE4SESBBl5lpj6ZnRyTCWhkuX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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