SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcb694dc36959f073be768f6f84397394427647c7ffdfa2716048cee39100a87' 
  AND token = 'MYdXthbsO8LxDV1hijem5c11BT1oNsm55yiJVipHXD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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