SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc168891f026351c9f82830a122ece81300b7c9f9d7331ca244ed4cbcb287dcb' 
  AND token = 'IHknoZ7gAaAF76lSQtplATp854OgH8IuyCAe4qcDAG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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