SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0afb4cf563701d9c7dc455a287dfbbc4c262459b63e38954303287b61c72ccbb' 
  AND token = 'QLbGDU2CYJ0rvVeMS8rO6T9ms2h48sV0TPI2VRXY5UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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