SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '55529a16027924a9b9461ca5afbd125b9aee081ca16c33b57947dc7603846abb' 
  AND token = 'A96r7pHRqo8DS2vAfTASUrzVj1rvRIrhRPRhn80ELnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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