SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca0b24d521348bf29b8388f92065d96d2cd6e3a53bc8618f57ee39d6ed6c3606' 
  AND token = 'vJXmlbnJCewQl5IA3tssIk3ojV2xZbkyjWvarrxEZ3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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