SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bd4b3eb87fd51f9ef45130c70a8d683d326bd315b18b029a5003d57291c8798' 
  AND token = '0wBKhxPKB6o9caDpW1ey4xi1O9FahydsJFBH/6zEvQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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