SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e20ab18a6769827ad051e0d5818c60f9bfac539439fde02279825e2bf7fdf5e1' 
  AND token = 'gBMKxvNG7KBAztvGm4svAZqn4T1E2g6VbuCkIOrSb6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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