SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '680566c21fc47635cce764c52a7107d76a1d059ac6ecd66854db8fbe7ee5af43' 
  AND token = 'yvlahy5uDON5jOskZ+Y/juJkOzr3VzgxUGXr2Q7VTX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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