SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '528715fb90e4fc02411f58b47577fcdf28b26c54372d5ef6ef7aefa1b5ab4977' 
  AND token = 'sHrX4lxmwM+rUg7K+sjQmvbSFxkI78/pJKOiqucmYDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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