SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '368ad102f08e18d000ab683fe27fa458c34aa0ebe25238a4a45a366be712db32' 
  AND token = 'Yi0NlQbwVhoAyhiACk3Zro/U/09qN2NN6rx8xjTYMSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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