SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c7be97b11e72b4a2f49a2ed2254573223c41277858f98d7eddffa8efe264fa9' 
  AND token = '59ZWlO47cWYDUlE5chDtb3p8dzh94o9oRmJWEkxy0WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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