SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1cd614e9a5bb65361643afab0af8011cfb9d1e4e810295aed4b7a45a4c32a03' 
  AND token = 'QNomJT2x2hgEYYZnUtjL/SsTS0Z1Y7OmDSsZ5ph8B4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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