SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be1ee10678622494fab72b8f31d1c31cba1fb466b4778c1e8ce36a0f3900eea5' 
  AND token = 'zSzyIa3nF1AFKdQg2RXDW2ZX0JFjWiqaLUemECc0zys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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