SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b9e1357dacd7f8f8ce75952a2dbb77e129d8cc7fa1ca5b5b86c1ec8666bba69' 
  AND token = 'epWL+B9BXAhQAkKAI8K+jQVp/4mTGM+PmZ3LiD6Vs8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}