SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd310aa30d48ed821e9aad9d8dcd355c770fdde7fffb11b9228acb57cc601eb0c' 
  AND token = 'dbIUYpYiLgnrdYRI62mlvM7Qyfpxgo9Y0GTsyEKN69c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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