SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aec17f85a2b5deddafc062f98acf552416c8801f42315f1b3545f702d6c5aee' 
  AND token = 'KT77II0bR/HxuQo24UY08R2rXu4gsd2QEVWl4VVxlAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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