SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bec250eb2154c7792030df754d4f6c22312decbe585b9fb33bbcf535a2dc0ac6' 
  AND token = 'HU4IpcB32Uilj8OQRWJbkamoi0BtQPQgyvMdRd6judA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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