SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a388cabb0992d5e26c02a944544c26bad3828b6e61459fa6c025053cd9247f6b' 
  AND token = 'JiZy5CS4fhDO+TwBOjV1dWFW74o3cwz6gkuKwNKSkFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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