SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '851f970194867dbe0cd666b56ede42e3b7e861b2736e52b9d7a1581a519c169f' 
  AND token = 'qp0saYKWk2GXF7b/vWpLcRTBtHKuDxtCXxIcE09jttU=' 
  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"
    }
  }
}