SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21d87a199a541ad1618acb7482e882232dea8740801e8a4503f29d9ad4119664' 
  AND token = 'qEM8xvvV4q3+kEgIxleq2rD+wFRcTzNNV8sTo16XWUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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