SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f384c6a1e068bef92d4ed1d67ac7a36f9d5912e546fcc6b91ddeba7fac0eaffa' 
  AND token = 'qbmDhAhihoZWqZZn9glJpA6KcYRYawFRP8SdGZsv2CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}