SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec1decd36eeb46cdcba3c443d9b1cb1a404c3a381b0cd5e981e16ef0947be80' 
  AND token = 'ILqCYsqnbV7HYo5NMCB3FZaJCMK4o3TGwdNxUDGEY78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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