SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9cad920b0d759cce749e7931f15036af179ee9794f5d5a86d6b89bda6b49f83f' 
  AND token = '/KSQ+thXaw7pbTCfKx4ir3VwJ4OQ8/up6HYcv+UWn98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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