SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83f35fb438fbc424a78dc2e8892bf06cec5cb32a44b142a01e427db379609650' 
  AND token = 'NJjmam7BaFlRQrOeUojGp3iOuGDVKSuUcsKTSxbrpOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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