SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c19cef432cf95246d4af884bc608297418e89099cf751c438ffe6ea9a0930c' 
  AND token = 'lAlefQUD2fmQO/DzxMYuLrSQsCUAXXUjPAVJm075dA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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