SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97809d7bb116aa8cdfb206ade43615b7fc9835da919287528481038ffb5982b2' 
  AND token = '9JX+gXUd2BmpedeGaXwVdv8pQgJraRDtNunnyDM/LPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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