SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da5e0a1dba413cfc4036b19a6be9bcb5b07d79a1739eea358c53dc27de89a7be' 
  AND token = 'Z83legjOqIZ2s9GkmKKkXCpqFwyB4BumrJNutndhc8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}