SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '079cc79102a4af006d022bea083d72226c9b6a87729ecd85016ab40b7d81c638' 
  AND token = 'y36sv6pByhg843pof5TWdpufGKRGqbqvi9qRzLpRKHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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