SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a160872132cf8daf55117dcf1234f41b4b5a2c813a79456f604496c660ac126' 
  AND token = 'ItOo9WbRw8loDvu/lRhYVHIkrqqa/vnyOYyMxzul1rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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