SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '811cc940ad9a29b6048234e9685a48b058fe3c08d70d3f9fbc120710c3d66a05' 
  AND token = 'pTEvIiuQ4dHUvowQL1u9l6YN07cVMA/baHZTWyFSo3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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