SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dd25964855538164bccb6da49e55e0633214e6c09a4d18cf8b52436d1a066b6' 
  AND token = 'rkvgSwcDelqaTQdzAutTs/jcWl9baYvQrmaH8Zu1kdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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