SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5979fb46b6d1d25638831fa8c20a96c0561aae7e827169980e1a6bc11933d549' 
  AND token = 'SFqfoP5IGMFqie5BSYrUASYUJT5lyECR+mIvc6L01lM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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