SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db59388299ca3239af472f08d0a0a3b826e0ada3c225af07a004247a6046f618' 
  AND token = '8jeL+NImHXhUfVcdvTFo6+VW3xa0J/kloc4KpZIYcCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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