SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ba273e665ceee189ac2c00f2431da6523ff3af45ed977ce0c4adec7594d0f19f' 
  AND token = 'm/+uKCbmRTo1vEkTQm+liefar5fgnvWDtY587BqVrnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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