Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e736a2f3d63e9664a3fa320fe80ed79942f57f0a6dffc9a7c02f2b9a0113dec' 
  AND token = 'SccWXrI1XSi+SywoZb8Zhk5aHY1SLd7MxfEj2kqFbq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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