SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06715b1c487d0a32cceb94b67fcfebc944f1693a9e1bf6b11ef79b18aaaf24be' 
  AND token = 'Mk8jvWMGNrRWjNls0WfwTNWTCHBhlhmap8LidApl2Jg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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