SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2829300ff0bad23fb6148ea4d6aa5bc047eec3580db60b555adeb3099824a635' 
  AND token = 'HizTDoX8yRW9c7+TdcYjVFXFKHIwFT5g+v59cS1vvVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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