SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a48c4b8d0cd86620503999ffd9cbdba13ba182c3255072db34f538ad26ef40d2' 
  AND token = 'NlDZMHFNfG6hxYZ1OA+BGar0VYzOwXBLys+Zh5tq+9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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