SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fe89122f50b2bf24c683f38717748684080fcedc756d55fa934855f9d9ed1822' 
  AND token = 'LwdpBqppPZUvJaqQ3tHTymLohGzzbAMGX8aaaCvuYQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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