SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f785b376f8e59a55d32389abc0780f5bd07bfd4e912adb58249c62553e1ae4c' 
  AND token = 'YNw/jFTGF1f4+OGWa9iE1xJY5QgaLmYTp6kVnnvgb7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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