SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9232e6289b863d29b5eed0009de01c2833b188434566e1fa8282ef0407d37a7c' 
  AND token = 'JNqca7SrLPtKKRh10cG9NO1rUJMKnLg4YSzFQm3sShs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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