SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09672df31d3a7ca0e1455d85b4666bbe9fa635896f444d3f362ea8a8fbaea60' 
  AND token = 'q/hR5MlnogG14mDNqo6nlXmOngAw7XQkMMsRPAdnBY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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