SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a356a4241f7ec04ad57d11b8568680c9b93de5023d40da7204a6062995fb7fdf' 
  AND token = 'NjJhxhJ0Bn+QrdHW9O3swC0sAPMxV7GFKqmcZO1+adM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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