SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33be9fa60b77510a3c447248f26611dcb2f389504695366f474a49c74fd72949' 
  AND token = 'AvE2GNlgaB7xY+zau8ulopVGfwyrsIcuBPRz8uGAGNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}