SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bda52f86c0ff656357ca042dc27d16024e41ae66cf93079b7b459c84ad8a8e6' 
  AND token = 'sS4eX3j3vlCmYOWn4Sl48ZiER//GKhxJexzj1B0LXmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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