SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff35382b19df2aaea62c402427bcae205c555b688481c05ceddfbbdf1764abc2' 
  AND token = 'acV/kiA1TkHPSzAqy/f6LNoEUb5aoxJFdGc6v6Ae5yY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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