SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df47db9a7ff54cd28ea2a2e85d1ece2bd68f97de426870ab8c82a099ad058376' 
  AND token = '2pxQeNYSthVLrnE+v0aYZKwg3K3PutnwZS+z/l2umTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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