SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3d9279487befa709239fa171bcdb2a27e6124ef2acc518c31a02d1fb876ffc2c' 
  AND token = '58sLI/FyDiLMo9oSg7GdX4SNVWKYzXHir72ip1cm5uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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