SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e459f4ab909e297ea7eaec733e2b990373ad381c00770bb711c05607a06fcbe0' 
  AND token = 'CWOcQ+ODB5EJ8ziEkNVvSXt4LYlpgOXCZ5JO/Iro35Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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