SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bcc98ce7c5600e34b5c26b6fbdf35605f9b5201301d55caafd9c0cc0e9705e54' 
  AND token = 'Z/Z8V+zKsueQWY+ywVFltVFJ8vvieUNJVcOSMvxdFFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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