SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed9f958744823ecf15985f8ac7c2ff03bb68db6eabdef0e63238d5abf1a68466' 
  AND token = 'KBiP9VIMs/Rclzjfx2QUwmZfmkd37Oej+xUxNmPGGDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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