SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a564db0de8745b4ab79d624d32dbd0e0343b41a87a3623926603f3f8606182d2' 
  AND token = 'ggD6TDArE/WoRmBgD44cyFINMVRlk/eM4aZVDjbqf7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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