SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '546cb0ecfc673c0f75df5d922fd8819ec7e1260973b8c6b6970d8fcd5f4aa4fa' 
  AND token = 'ZAQ4HrKOVp9xykQbcqmz3ZRjeO39Q+Ov4uNYdG9YI6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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