SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68d73e5250e18707628fb7954b0442d51260b1bb89bf3409d019728cfc831068' 
  AND token = 'mJFMVputTr2kiBnODYVmeWYIqYUbhdCX5l5DrrmOnOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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