SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb2fc9744c5230233f670d79f3fa5cc627558c92f028c54c87750df58acd0e33' 
  AND token = 'k5hCFZuV83eRFJu7IrcRKu/lFsiPaOAJfkFPf54A6pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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