SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bf307fbcc32c19835a0969eb66aeadab75e46aefb8107b9fc15390e0d706e6a' 
  AND token = '9uDTN2c4zW/F/c+DDCutolnXlOifRbBf5VYQl8MwcmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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