SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd7818f2d6f9c397f2096c8a36fbcc216cfd5c8fdbe265f20b7357f49f4981ec' 
  AND token = 'j5SlskTnFItAX+gjlix/6d3kK9JBHvI3QwtU2rZcMQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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