SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd189d3471bc6ed4a5330e98df0dc32d2e20bb65ad33b40502c0ef82a9085a4e0' 
  AND token = 'xlFujLKFVKITK2Y+mfy6Y4znuUNNLlz7usNcmXPsWhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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