SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8976abd4d9894455d8dbbc9b5c92c0e8a67c9f0b126bbe7f7aaf0b632f065f99' 
  AND token = 'OAotJM10gzZU7rG+ZGEdmLC8BGVMhTv/u8IDCEYIhfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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