SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479b8998b17b2dae5ed726ef43a3040448b5bdf9702bc0cc034ea1976802183f' 
  AND token = 'TxhmJLY/INbODf8DRbsQloxXrBuPQd3KMDNVpe7kpKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}