SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac6fdc825822dcc0bc7d44200a085ccdc8b80f4143eec790c82fa995996eeb8' 
  AND token = 'PZPx+e5w1XlSKhoifXl/rRW08hhaQxMp04eWwjlqJFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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