SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aa76eb12b7716b81769c3be0f063e31270e41402ad8e796c17f084633764137' 
  AND token = 'nv0UAneHO9SS+lWrl8IxR4IFdM01NDOZPiIskNdvrAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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