SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27566412bfcc4363c0d58ce075612587de90c12457034290352cc91c797bbf29' 
  AND token = 'rbNlTY0VVeFvt2B0OHrmqfHSmF4aDKzZxJkcGXu9l4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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