SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '673bf27549988e82e77e3b48d20074962b9afdad22af1f34b38c4db72f8c4edf' 
  AND token = 'm3MZa5q+NvyKkA2C6SVeJKvi/0ZYHcoISY5jmBu4gYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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