SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94e656c63a9f6564f833ffd29354b62ec95136bb7905b7f3cbc95c424c16e3bb' 
  AND token = 'Eyzv7wti6OZmC7gn6bqxlOglexHF2GJVkAHktPVCxGI=' 
  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"
    }
  }
}