SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23ee66252cb6c85136058e8654e753c2c75909cd562b9888b3e81071845fe94a' 
  AND token = '3wC01YyTZ7DlJBK5PAT5v/d2Lhz45UkX27gz+EWJECU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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