SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '194773c2f54142428854eecc7e43d46be2491f288319d3ccda22127cd7b54149' 
  AND token = '/PU6QCmHLAZhgEJ6KajCbTQBdHVhzKlRfEVCThr6pS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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