SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d28265242add7dcab7859288fe3ca334da5787b4914002177081ba0685a7d89' 
  AND token = 'nwqeFtY4/Q4qO6vVchd7oFqjaWIpktZ+caNXJgwqY6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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