SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5896432c7411d27b9aeaa7330f0a3d9635851297300c4d3d53ae2623d3981de1' 
  AND token = 'lm277avS3GIkUW4wmijyVKtMDbW9oOEw+nlkMqioH8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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