SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38bef601e3e5329fa9fa0d33fd48776df628cb0e9fc527a10b45221cd0ba8d5f' 
  AND token = 'QgfHbBzeqpgrdfpdupmtoNOQIjc3X9cvNpE9oXrrwuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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