SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c850859fb22e4681523e10dcae42a905bb00b50b5ec70ab2f3d6adff347e60ae' 
  AND token = 'V3TOnHJQJ/5oE5Mh0lrm3tYwFLXeuf3KnYgLvHEQS0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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