SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4de88b9c443f595901bd5f89de27acf2a1f204d76dccba7e5d393c75a489fe82' 
  AND token = 'RPoyF/yLz7Zx3zgVG2qHcGAjHQbDwi3m+ihvWIUvP18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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