SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3a57d0be85bff438c6ad8740785ba0d9605380b012352608cbe6c3a151c67bd0' 
  AND token = 'ov0YjzrT7eQuyZp6cHTbhEuFL1NyGZVaHqXsAbx3MZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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