SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5a4c100ee7041e8b2eb8e43512ca87a3e391f7e1a02b6e14d79bc3cd0900755' 
  AND token = 'qt2KguRQi1k3U1nneOaKt/PdHDdaesnXxKcQtd+to+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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