SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '401880e2654fb9eb592e3181b47cfcb6362f157bb93a3f625e863c608d2aebd5' 
  AND token = 'IkhHyUnSv4ULTB5+o/5QnyTYLHMdYm+Zz25PzS6aPGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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