SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7253a137bb5b48f1afce87c176fe76a3d7ffc72a66fee565daa408493810077a' 
  AND token = 'Nqhy2hrxGxZIR+du0Ar4ZJRYNOjUzzds8SWysys0TYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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