SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d885b804b0f82ff3cc1cb0333079eccb3b7b758cb8b0b58f2869255d6fd19d' 
  AND token = 'MdnTYU4BT4aEo4t7f3ENK763vway0UsuWLgRYTBcc0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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