SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64a42b79ddcdac9d178827ea84e75f348b33043243af05c61ffcabf745e21ee3' 
  AND token = 'g7+bWiusVEP1GNBcJbk77YyJ0TMTjJZxCyvClP0mgOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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