SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74cbf34c9f984a6d31d8921fc3b3ba1581fbb1d8e625b49b71bbb440bb054551' 
  AND token = 'qvDJVGkqpx8IcURpmq/xsayK8FVLUppPvKu8glqV+4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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