SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7281166fdfedb79324b5a464ee1646783ec636cc78897754405e66f211500434' 
  AND token = 'CqdkVyNUZ8my4sPVCpchN27du9hbEa/KOccogq9x0gI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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