SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69fd5afb17836089705354d88b72bdaba630087451a44e3499ba0f82857aaada' 
  AND token = 'gUcL2nYvKot+EtOHMaRQh/5UkhmQpSHzUets2rS38MQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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