SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87192c9bd0c3b039ea3115251adf8ed22cc7745181e9a42a467598472c4af9cc' 
  AND token = 'TkFnmxZA6OMJo78wFTB3pODT+dfWAbo8WbKqIJwyZkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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