SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1400684bc775f5f848d1db4ad84ade09825378067a591a5fb5a69e7f33be950f' 
  AND token = 'wdyaklJUp6jPPKqlWZBX5G6DoPl1YPRzNKZrw1NmALM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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