SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5210d690377091fecc6493af5ab2a46e7b8d01504fe994bccf972f7b5aa529b' 
  AND token = 'KySwpYAUuoVUEYHIN7EDNgAZxo1jxcz1uQzhE5LENTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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