SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b02ef6fd9c61261a57240527f6f07651934ab17d78853c56ff8b22e41d4cbfb' 
  AND token = '4tQu8LGixjKyOiiHF983gWWK4Qf+LX/h/DQS7J/CATQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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