SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2374f5f93b1f21aa872c10f44b2286e47a5f8f21488cf5e0d311ca63092c4837' 
  AND token = 'i6kQVUXzV/sPo/J+ab6Vk+nY1SxgLYFFy1nryGzLLyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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