SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4499bed7bac45f8c3c226105b403d961c1c316b2b350e2758d4d898bd1dbafde' 
  AND token = 'j7LZd7sIxPslsQQZGEqIYyZO3w/relWi5xCwAS5gEJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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