SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58b6c393b34afc8b3481cd71f3130798f24304741561eedb132980bbf790a517' 
  AND token = 'szFSgqOYrwFxr/Jg/htg12vjkmy8CHfzhhYBiUOs+dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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