SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9aeb94bdad743c072f3e703fa1d35735f2ad641afe4f47363810e12d8cd6fbb' 
  AND token = 'v7litQGcelG+6BwU/yJ1i/vBppFuWZntxIg8KlY1T6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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