SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d00bd13b8f80e9e7bb50184e3f53a9bcbeae7097f8169ed10b2b00a7c54bb8b' 
  AND token = 'zhj4LSxCFs4xbPnvQWRgBXrgk6+NzG68PQT8iUmIKfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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