SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46bf45fd9c87130f4be5d8032e630fa18ac71e50cee37e1579172e12020428fb' 
  AND token = 'QLh6ZOHO6075udljFMfSnre8GYUTIQBisvf1+m0Zk2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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