SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed40c7b3a2adf00ad3789b7b760ee4883f093f396a348025ee2215fb8e92b61' 
  AND token = '8mVyBqEAnpRvFUUoOQ2zcKF2CBo1L8QlWZWqFTUsbHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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