SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e6c7b23350a0963079e54e7a9361b25f9298c7512df14d5b50732df34e6e4a0' 
  AND token = 'xdzHcButzWHwlEA52izJwlThOoAcq7hDk/WWV+uiFuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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