SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4109300b12065e279765e2d723fe0d38cf79d0e1dc2ed5a10bb8363c445fc47' 
  AND token = 'Bzzh5YILwAfyidi/ou0jcWgneYvRO+619hKarhFjD8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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