SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad08129b34cd56c91076703df255fdb7887dce2ca622297fdbe13778c7062d62' 
  AND token = 'XLcUc3QKYgHUBlHG6yWhC4giVMpqSuQ9qCE+asSVuy0=' 
  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"
    }
  }
}