SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0dc6d5c090fedfa557c91407837a5a95fb8191dc54990dc7aca491d1057d03c0' 
  AND token = 'RW+1RHpfIE3nUZJ7ndUsJuUw27dRoSKFjcSSirVjQ7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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