SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e3cd2853d459bc830687c640bfe9af9f4524edef5f0a08be89914e7c3d4beb6' 
  AND token = 'z1i9tav9jSzH9cFdOC5CnNQy4uemFmrzF+YslqnVxkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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