SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cec95fb1c0db537137cb44b20356823752f2d325eeda2ed2296763d4a8454a9' 
  AND token = 'CI9bBjJBfga7dB3QT6gzvQgq6dtckQsMtwFQq9FbFgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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