SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7960dc3a16708ba19efcf526a48cbb3ecb126978c1668274f4a968b9b8e763cc' 
  AND token = 'GPjc0DtcchirnVmrO821aTIaY8RFFeuPgPW5s/QH50M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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