SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b9437075e5c5250ecd78d67e3c7ef64c5226270a98b2cb44a4ab1e2ef5c2cae' 
  AND token = 't71OWe8xPanKBK8w6wG1YbXOc/BWSMHqan1lZ5xWWNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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