SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4503c6b8ae04a3eeec9c0783c0a39c69d1cfbfe299ba6064b23ea508dd372be' 
  AND token = 'fbIqzPSAZD+vVJOV+auriQqqGcwMQrBJSbhtzcUFymQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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