SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'da38c426e777bb3918595287bdaaaf1ce3b8fbeb35184e69ed24190b149bf17b' 
  AND token = 'Os3Z+SOPtRHbHMIfYW5gGE8p+w/qFRKn5KUJLSuCU0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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