SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '109fe08e8646c1b738f1d9a16f90061ff3a9246a46d2d152d11f7274b4fe1bdf' 
  AND token = '5zTsk4gG5VTY8uLVUWWM6OKo7BQEAd5S3lnvDjDY+LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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