SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08caeb88d2c1f179dbddb1c4bd34efb817fcb6d8ee5ffb1606c00daf06f379d0' 
  AND token = 'QnbFkh+ekopYs6juFM01jGQ8utkW91RKSsBqKr5m4Cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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