SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8402348bc529a07ce9b0b8ab089ea27f9dbdc811ca8feb04b70a338cc97009f4' 
  AND token = '1ZvpsVLtZz83qFu09eA4hav4PFJLJsnjs1qGksFjzsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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