SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cae8c7dcb21edc02f55b618392012ec49975e0d68fe5745678a0bb052057b3d' 
  AND token = 'mOIqdYV6SPsLSeAmp23uQ/6bReVAyEaiuqTUpeezHgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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