SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f922cc6c623c691cf9fbe6f15006b5acf7a7d6380b20cffbff6cbfaaca9cd5fe' 
  AND token = 'jFOI3Oid9tLZicF1LBB/5Keb6vEhPnb8hv525ZRS1yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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