SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de6b54b52d848070df3b3c91a7ba4523b6ea1f7866098d13825a0591f981d803' 
  AND token = 'Wkr/XYBNhArBf6pSPKyrqy3wqLxXyZY8hEPCzhGx/WQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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