SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '266078efc9bf89fa9aa0ed5d1dbf34c61345c2ad5d37ff6fc04e5290b709a365' 
  AND token = 'GtX2oTBO/+4aA/yRnjGWq/XnCBXHMXRwH4qhC1VMY+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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