SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c52493c8ebd56f3b5e4b272d0f3eade8297037431c5e819d0eeb9a148014ba79' 
  AND token = 'OSqKHYwmGICJZp/sLhdxGJw0fk0BTd/KIe+RWUeYWRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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