SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43bf6fcc21dcc282ed04c9824481b4a6af1e88b7896708b7b39fc073435a5054' 
  AND token = 'TvdK7v5BZTnhtBz73bjRiRVOCw6+A3YzvfAEeWPIKWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}