SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6692de980ba512d6cc0b19a27485c2bd1c8560d28e693b068496f1fb397505b' 
  AND token = '9x6hCwhFWFvV9lNCUvzgZZmPvmLu3WRIiDcchgvu+UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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