SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdf6937f5f8c4cceda38dd385694cd8982a967214bbcf98c7ec150d5d8e14606' 
  AND token = 'xQ+V9+LHMMeqmbfdVw74Hz9hYK5HesAz3la3jGZ25O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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