SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af3dc6735f11c2817b5282da39c7e839b0e4419ae31f707f73aaf8311d9cc0bc' 
  AND token = 'nCEd2F8/z6kRUBz7dtI7dMcDQODOs5fcxJXRCsjHbeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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