SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9283092cdb06ad68fa579c5c19518037c3093705ddafe001165bcb3a5976f68' 
  AND token = 'rugh9gqqz0UToseYzjtkgUoLXBy/JK+7KM8N9BbRO9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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