SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66715210a2798cf8b91f8e7dc465e522cc1703357569f37bd0df295d3349d3c8' 
  AND token = 'gRv8AEVNozlSXq8nZX8SLQQEwT2rVqX8ju9qLj8fbhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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