SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '770cc3ae51e561ff22368466ed55818ccdfbb012c8b3762dffe68ce4f92a6db0' 
  AND token = 'oYGd2626tU9LMUQ9D7Wcxh+av8n5OuXSbpbYtX4Wrxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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