SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267685e0121632d5887bdde84621b10c5f6d0ba896d30527b7f61f2ecef591e4' 
  AND token = 'KpG9ujz+5XSMnxfxKLEn9I3QR1gOckQ0v5mK/zmuUaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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