SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '924b2deefc41d927452aebc5b568d64fb44ec326ca7cccc0c3ffcd22436aff46' 
  AND token = 'qNiPCoVejeZEVJZC7S4YFQENqbENB8EvZ5zlTQEpvLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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