SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb1ad6f39287be638706a98507ca9102cff9b458c31f50008f8cd154654d24f' 
  AND token = 'UyYDK+JFoFRrKZfHL7mK9QOmRr27GW720wJ0RUoumF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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