SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcc4aaf89a7146a61b463be43f3a1616ce8142c617ce906126f275daa6cfa70' 
  AND token = 'iH2mZwt0OEXyx83SQpYR89NXpPbkBZniZ5umEVwdnNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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