SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99bfd599dc92c48188e8cc1896869ed3bacbdf8284ea02ea867ad05f5b6ef080' 
  AND token = 'wcBJlHTfq+OgwCa6PMDUguvXVikFkWDlLWOmpE4VeYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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