SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '635b9ab95ac73df356ef741e56e325b56480948a913c6a3db8529f018ce30ddd' 
  AND token = '6K3zwS3a7I9OvYj8rA9NG/mYrlCVZuX6xt8PHhEnoE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}