SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '367839a0a5e47edd67e6bbf5471e1cc7c3b9398510a5299d6c5ef69c1bc1aead' 
  AND token = 'eWEdKujwLxIWcwwPZt1heuutKaoZ7Nre/ZqAv5lFCVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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