SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efa6622b7bc780eacf61dd8259f4101646c3e1fe25f016ec28c67f8c9299e99e' 
  AND token = 'fRSK7i8TFyZswAIpevQuAiK9ZBU0idpQk0u+NXK8OoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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