SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99de0c03f0527f4493378fd875cd5b3fdc45c8df4fd914cc31b9a81eeef04880' 
  AND token = 'XcXgYqLae5BWpc7bueBXvF2liHbXNPgHKM7RUcz7Bzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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