SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09e1ec036b60368d2307f5131188b0093dae54dfe757db19a8080961d6334ed1' 
  AND token = 'NjmGD86FRTXppKoEo1zx5tRxFQcfT3zlfHpdhuBTeEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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