SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c320e702a6ecefb0d066ffb5c6fbff772b6e290df17940eab8d0682956df61' 
  AND token = '19SjIrnr7ItFt9j95CXlHcyTtVGfvgFHJm/5XOnkaOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}