SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8fca69b9701f56e4f21b90df08f1809c5b4570173823788ca86b1e4de47a963' 
  AND token = '06YWem5qiXqwKFHkVfpzh5ThPdJyXa9GbSMzbsYn+lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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