SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd724b8ab2da55a5b39775df46a10db7c3e202d2945c6e4f069c7a8396e850163' 
  AND token = 'UEv7APwUvLVoEUEcZyCd9LMvEPhyd76Jgzvvzqse4Ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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