SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6297a1030bf3753bb76369e1ee0da16c87188334adf589c40570286c5c499064' 
  AND token = 'p8UoMlYjscdNQKT0xygWcgyQzVAI6q9H1Gai6zuObcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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