Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8878d135356ffc1c69710dad6a01c6c7f0c2d14708e374edf1a43eede2308d21' 
  AND token = 'tQcsjydiGPfdiLWRISRsRze6WPcaQlObZRiyQIjRhQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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