SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82c4e7ff20bb42a91b45326c2a41b64a6b1efe71a74af9c7a1c6d497eb17c6e3' 
  AND token = 'fVYb9yKe54nTaVp8hjKwGZSIi8XQWbWsavpnXkCEeCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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