SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f60de6e8879a7a24a0191cfced7d5ce85d6abdcf8e6ed02bb6ecddaf6ddf48ae' 
  AND token = 'ar8oUB9fHLUshzDLl4ZNGzu9JBKioDL+gbJbyGpC2D0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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