SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7299a8fe0ddc9a86890be3f1e9415591eb617d6eef991683683531ccbc91bf5' 
  AND token = 'jvKQVkFfAanNN2/7T9Bnu/qjZxQtYGFb2mdVIsq/Lnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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