SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a5679bd3d0af01fbac02900653e449cc460137cf914ebdebc3b456fb3b64ad' 
  AND token = 'Gp0sLD13y35bScuUz+N1VaUWbP2oiOv7iEkSETDOlLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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