SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd238df1e25790195e302fdcaaf968d9b4cd02c0ae1888c1ef394da66f588329' 
  AND token = 'Ym2utxvUnamtJRaWPzhKS1HJb83i4F1gmfamiHwiXQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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