SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd92f73b8f7dffc2fb612e6e73f637daf0be8389d57bbae5c111c88ea3af984c0' 
  AND token = 'utzibgmISt4+mvJkcZKPpjyVH4qVoPWpFEtc18IIEJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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