SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7a289c27f987c307ae835492d6efd1e6aaba8f73d59b95f269710694fabcfcb4' 
  AND token = 'LHZtsLucSd9GNzAxIvlQLTRRcTV4V9MR/thg0qpw0RE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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