SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f25fb582b8f05368cf8e7444766ddd1c5e95c549724a40c352b9f46f5c8a4e47' 
  AND token = '/mZlhbyyX2atC7RxCo7wpZrhVuNIuzwX3rCKM5BmZPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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