SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56112483bec5af4626703a23cc17abf27b9f38118883a4ccb7273e03c1cd36d' 
  AND token = 'hnYrM9eHYTDdITVYDyzNTK4+kZwf8xym6PLjJmGfjJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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