SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '12b4af0eb055b90eee14823057acbcc2859ef2477eab54db62e8d984ccc439b8' 
  AND token = 'K11TSWL67XQLxzdxj6d1pjwmOdtFZqFoveQLaFTh8xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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