SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '810353b9958f96271fe4a62fb17930123e7888f33bcc289787ecd1427a954fc8' 
  AND token = 'nwQOLckbaq/WAr93DYySZM0VIX7DZI0zeUjWeh7IPmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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