SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522df469311133a001d071fc8ea95136662ee263998ae6b7d9d689c38f87a565' 
  AND token = 'WlDcDRro/bfVU2FQtcvMRNh608SfBOyG0RIjhhFmLuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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