SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2312e638f6a14de56fbcdb79cb18d73f4153c663b6947fcb662a36a444a09807' 
  AND token = 'GnOX0TwRVyTG+OF37hAC/2PxpctDKqkcBumNxbOwSKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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