SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5362dc1c26f45200d973ee4ecc21a59782001a4e881852921192b39259739fe2' 
  AND token = 'Vvqh6NxdjrVmW80uItwgE6k7yiKcXrRdqCvug8jQDXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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