SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97718a8a7e33ced6695cb2702117bfbfac4e1f1f78180eb8ff175f49468bd022' 
  AND token = 'zQOOW73+ZabBf3pHgpJpMpB5DPXKqv1ggraDE+eUoUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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