SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ee4b47c691e04624c8a5d948a565e933eb300fcfaba3393d2360466e88b0f65' 
  AND token = 'a0DFKvRrmFF8BXZA5DvG5t9aoDmPGO1VBJPgjySy2+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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