SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2755384700a96f73c79871687ac3b91b9aeb8af16851f0444a3d40a04d71b2c6' 
  AND token = 'YeIFjbmlqbNa3hapmNzYqYMcnrsU6vDlFPUjvqzZavA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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