SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35db1a3849a68cd838dd2496d7bbe277af0613d028c0547d853e027cbfbdb895' 
  AND token = 'exzLZg6W5/LpLPMtr3iltemgbOlHxtRhuXORLkV/d1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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