SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01909068ec6cfa9d266a72f05a1dadb90298876758dbd4d349461f51e96661ff' 
  AND token = 'KUZ0xA/qDOjTap4LVtClZVVDVwqkRs3D1Ybztcgg1uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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