SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4c20ffcbe57f82633a8e45b604ad4564795817ca9f008494bff793d26ac980a1' 
  AND token = 'iVQGC+xHdXLWoihknEIKR1td8getQGmqWx1xi1Mky78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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