SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99ec4d8b159c3684e61abb9a471e37ea230b1ef69857ed14fa68af5ce44d2188' 
  AND token = 'Yyddg5VQWAzts68gh1fLhrHdZoOuFVoY7w1zCoWzWsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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