SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c430968c8a425363308f8bad5b63505a4d316878490b761bb80ac5f0ea80039d' 
  AND token = 'flDYuj/NoY1pvDZHTm9tLhb+cP08SQAR3RWlqXLjvvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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