SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8e7b87855334751fe6de999f94692d2c92985e43dea4a32397a69fe600f8bd' 
  AND token = 'ZgGocfdukqptVXKUQK2t7qbZHFzNGYvLBKpKEKD0eb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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