SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5af560a6b026f5629c37f4921971159b5cba17b94cbb5b64480d086638d6a6ee' 
  AND token = 'a5FrNXtKgkU/kxjQ4s/pYB85/e4VAlMG5qTchkapOoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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