SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '437597046d009260fa54fbd3d163072fe82e179a5f4e8cc258007580b517e598' 
  AND token = 'qdfFITtTKHu+rovBMAjhhZRQwtwq6kKBTyku4oa6wTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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